A company I worked for bought a iron Duke equipped Chevrolet Astro van, about 1989. I had the honor of driving it from the dealership. The gas pedal was mostly a volume control, stomp on it and it got louder but didn’t seem to accelerate any faster.
I could definitely see that. Even with the 2.8 that van wasn't very peppy. It wasn't until they put the 4.3 v6 in it did that van gain any real capable engine. That must have been a really low end, if rare Astro. I knew they made them. They probably didn't sell too many for that reason you made. I know that engine wasn't really powerful in my Cutlass wagon, I cant imagine a worse slug.
My parents had a 1986 Chevrolet Celebrity with the Iron Duke 2.5L I-4 ... I couldn't imagine that engine trying to lug around something as heavy as an Astro van.
My parents had a 1988 Astro van, I remember reading the Haynes manual as a kid and wondering exactly how it was supposed to even move with the 2.5 liter engine. Ours had a 4.3 and it did just fine.
I had a 1984 Fiero with this engine. Leaked oil and sounded like a farm tractor. That said, never failed to start on the coldest New Hampshire winter. Totally trouble free. I actually liked the sound - that of brute force simplicity and reliability.
The slowest modern car I experienced was a Ford Fairmont station wagon with an inline six and automatic transmission,seems you could floor it and it just lackadaisically sort of moved along accelerating barely as fast as normal unhurried traffic-strange because that engine was larger than the Citation V6 but I had one of those loaded down with about half a ton of someone's mineral and rock collection and personal stuff (I was helping him move to a new place) and the loaded down Citation which with that load weighed more than the empty Fairmont still accelerated quite a bit faster. And that Citation was not as fast as my X 11.
I think that car shared something called "5MT" starter with the 2.8 V6 and the Vega. I think base models only had 275 CCA battery from the factory,V6 models probably came with 350 CCA and there was an option for a 460 or 465 CCA battery in the V6,same battery that a pair of came in some of the Diesel vehicles.
There are two great replies already. Also, Iron Dukes use starter shims to get pinion-to-flywheel clearance correct. If you don't shim it, you will have noise and eventual problems. I always wished I could have bolted a Chrysler gear-reduction starter into my Fiero's Iron Duke. You start the Fiero with the sunroof open and the passenger will be startled.... "Wait.... Is the engine behind us??" LOL.... it got more fun when they asked what the buzzing noise was from between the car's seats. Man, I miss that car. It wasn't fast, it was hard to work on, but it was fun and fuel efficient and had no problems holding 75+MPH from Michigan to Maine.
My college roommate bought a 88 S-10 with the 2.5 and a 5 speed, his first new vehicle. He drove it 498000 miles before he sold it. It ran at least another 5 years before it was sold again and never saw it again. Noisy, but very reliable.
Oh yes, I remember it well, as it was very distinctive. As far as the worst sounding GM engine goes, I'd say it ties with the Oldsmobile 350 diesel. Not solely because the latter sounded like a diesel, but because it also sounded like something wasn't quite right under the hood of any car so equipped. And...my mail carriers still drive those Grumman USPS vehicles every day! As you'd once said...."GM engines run poorly longer than other cars run at all".
Just because you don't like the sound an engine makes does not mean it is running poorly. An engine is a large collection of rotating and reciprocating parts. It is going to make noise.
My mother was once pulled over by a cop because of all the normal noise her 5.7 N diesel engine was making! The cop could find nothing wrong with the exhaust & so issued no ticket. He said it was the smelliest & filthiest most disgusting truck he had ever pulled over! At the time my mother`s 1978 Silverado C10 was still under warranty!
I remember that sound like it was yesterday. Growing up my neighbor owned an ‘81 Skylark Iron Duke…every winter morning I’d hear it starting, idling for 10 minutes, and accelerating away. During the same time his wife drove an ‘88 Celebrity Eurosport with the 2.8 MPFI V6 and the engine and exhaust note was impressive to me even by today’s standards.
Ah, the Celebrity Urinalsport. That's one I haven't thought of in a while. My Fiero had the Iron Duke, but I remember the 2.8L V6 Fieros did have a nice sound too. I liked the Iron Duke a lot. It was hard enough to work on, I remember helping a friend fix his Fiero 2M6 and being really glad mine was the 2M4.
I have to agree with you. These things have to be the crudest engines GM every built. I remember working on them back in the day we got a lot of these in for warranty making noise. One of things they would have us do is drill a small hole in one of the oil galley cup plugs. It was right behind the cam gear. This would allow more oil to lubricate the gear. At best this was a band aid fix. It did make the gear last longer. You are right the noise is generated from the cam gear interacting with the crank gear. The repairs we did did improve them a bit but they still vibrated pretty bad. The balance shafts where a God send. It smoothed these out a fair bit. Another issue with these is head bolt fractures. The head bolts from the factory where actually too hard and did not have enough stretch during thermal cycling of the engine. Over time they would break. The repair was to replace the head gasket obviously and with the head gasket you got a set of head bolts which where actually softer. The torque sequence was also changed to a torque to yield configuration. As you said these engine where reliable just very crude.
If anything, the phenolic gear would tend to dampen noise. I found the noise was changeable for better or worse, by shimming the rockers. Too much though, & it wouldn’t run right.
I had a Duke in an '84 S10... unrefined it may have been but it was just a brilliant workaday mill! I live in Canada and that machine simply worked no matter the temps - I recall many times when it was near -40° and she sparked right up and went to work when my other cars didn't start. She made noise, for sure, but I had no qualms taking my S10 on a bitterly cold Christmas eve on a 450 kilometer round trip to pick up my sister .... and that is just one example. That was a great little truck! Edit: I failed to mention that it was Christmas eve of 1998.... the truck was nearly 15 years old and had about 170,000 klicks on the clock. Just never a worry.
My uncle used to have an 87 S10 with the “lo-Tech 4” and 4-speed manual (Borg-Warner T4, I believe), in lovely forest service green. It was a great little truck. Slow as molasses, but dependable. It was his daily for quite a few years, reserving his lifted 77 F150 4x4 (which he still has) for towing and other full size pickup stuff. He sold the S10 after he grenaded the rear end. Those little 4 bangers are practically bulletproof if you replace the plastic timing gears with metal ones. They’re about as smooth and pleasant as an old Whirlpool dryer, but you can’t deny they have character.
@@andyk6796 I worked for a used car wholesaler back in the 70’s and 80’s. I remember two occasions when ferrying GM vehicles equipped with this engine from Chicago to Milwaukee not making it home. I had two of them blow up on me. This is in the days before cell phones. Oh what fun. Especially in winter when both of them blew up and it was damn cold out!
Interesting... I must have been quite lucky, then. My 1987 Pointiac Grand Am had an Iron Duke and it ran like a top with no noise and extremely reliable for 135,000 miles. Really enjoy your videos!
I hate spamming this comment, but do you happen to know the officially prescribed method of accessing the distributor or distributorless coil packs/ignition module on the transversely mounted iron dukes? Does it involve the removal of the intake manifold?
I agree, we had a Old Cutlass Ciera with the iron duke and I never noticed the noise. It was a good engine that really held up to a bunch of teenage drivers.
@@clivevreeswijk4555 I just barely ended up doing it without removing anything. I did it virtually blind, operating only by feel. It was made worse by the fact that the two studs that the two coil nuts go on kept falling down into the ignition module, and they didn't stick up far enough to thread the nuts on. I don't know what I would do If I needed to do something more involved, like remove the ignition module/crank position sensor underneath the coils. I don't even think the late N bodies had the dogbone people are talking about. They had a transmission torque strut, but it wasn't under any tension and releasing it didn't help rock the engine forward. Now it runs, but runs rich at idle, but is drivable. I can see live data and it reverts to open loop with only a 45 "oxygen sensor rich" code. I'm still trying to figure out that one. Maybe an intermittent misfire through leaking spark plug leads? Or a failing ignition module. Whatever it is, the computer isn't picking up on anything other than it running rich.
This is the second video you've been hard on the Iron Duke. I've owned dozens, yes dozens of them without complaint. Easy to work on, parts are cheap and it's great on gas.
Maybe you have an answer! Do you happen to know the officially prescribed method of accessing the distributor or distributorless coil packs/ignition module on the transversely mounted iron dukes? Does it involve the removal of the intake manifold? I lost spark on an 87 distributorless iron duke and am suspecting a bad coil pack or ignition module and have no idea how to access it. The V6s had such easily accessible coils.
@@gregorymalchuk272 Have you tried asking this question in some relevant car forum? I wouldn't be surprised if the question has already been asked and answered somewhere. There are also Hane's manuals for your particular car, though the old ones were much better than the new.
I'll also add that these engines are great in extremely cold weather. -40 start up is no problem. I've also had dozens of cars with this engine from the 1970's thru the end of the 1980's and never ran into the phenolic gear problem. Just lucky I guess !
@@HAL-dm1eh I'll try to find a forum to post it in. It's just that most of the iron duke stuff is in the S10 and to a lesser extent the Fiero communities, but they don't have the same setup as the front engine, transversely mounted sedans. The consensus here is to unbolt the dog bone motor mount and swing the engine forward to gain access from the top. I have the Haynes manual for the N body but it doesn't give much insight. Though I haven't read it cover to cover.
Definitely durable. I have a good friend who bought a new '87 S-10 pickup with this engine. He STILL has it today and it STILL runs. He doesn't drive it much anymore it mostly sits in the garage. Sentimental to him. But the fact that you can still start it up, head down the road and have no problems, even though it's never been rebuilt or had any major work, is a testimony to this motor's reliability.
1982 Skylark 2.5 had the thermostat on the back of the head, with a spout that had a cap like the radiator. Thermostat had a handle to assist with removal. Such a super useful design. Replacement of thermostat took mere seconds. Sure wish this was used in all cars.
@@fastinradfordableA lot depends on the stat too...I once had a name-brand (which I won't mention) stat fail-- in the CLOSED position, no less!-- in no time, like under 2yrs /20K miles or so.
Had one in my 85 Calais, and it was so faithful. Once bemoaned to a Russian mechanic here in Canada that I wished I had the 6 cylinder - he scoffed and said thr Iron Duke was over engineered and offered to buy my Olds on the spot.
I love the old Iron Duke! I am having flashbacks of that low-"Tech 4" EFI system.... LOL I think it was a great engine in the Fiero because it was all iron, and until you learned how to properly burp the cooling system in a Fiero, they would have bad overheating problems. Starting up the Fiero with the sunroof open was a great way to startle a passenger.... "Wait.... is the engine behind us??" (Wait until you notice the sound of the electric fuel pump in the tank between our seats.) Now if only I could have bolted a Chrysler Dive-Bomber gear reduction starter to the Iron Duke.... Pretty much any car with electronic ignition or any form of EFI is going to have electrolytic capacitors (besides just in the radio). I cannot imagine how many cars must get scrapped because of bad capacitors. They're like little storage tanks for electricity and tend to look like little beer cans soldered to the circuit boards. Like beer cans, they go stale from age, but heat cycles (Cars are bad for this! Think of the hot car on a sunny day, then you turn on the AC... Or a cold car in a northern climate, then you start it and drive it) really accelerate the aging. My 1985 Fiero 2M4 SE was about 15 years old when its capacitors started to get flaky... and I had just rebuilt the engine myself in my driveway. Symptom I had? No start. Good crank, great compression, good fuel delivery, good spark, but no start. One time, stranded at a gas station, I pushed it out of the way and hopped in, dropped the clutch in desperation, and the engine came right to life. And it was consistent that when I could not get it to start, I'd roll it and pop the clutch and drive off! Infuriating. And, of course, the sort of intermittent problem that a mechanic would not be able to reproduce without driving the car every day for a week. In an automatic vehicle, it would just present as an intermittent no-start. Remember, every single day after an electrolytic capacitor is manufactured, it is gradually going bad. An EFI system with original capacitors will become more unreliable every single day. Until your Grand National won't start. Or your 2006 Toyota Corolla just throws an untraceable Check Engine light or any number of a million other problems that will happen with ALL electronically-controlled engines. Used parts will NOT help you long-term because the capacitors will be just as old in the replacement ECM as in the ECM you are replacing. My background is in electronics, especially vintage electronics (radio and TV sets). I was sitting with meters reading the 5V rails to the TPS and MAP sensors and other stuff.... All looked good during cranking, solid 5V. WTF? I was working on radar video systems for a major US Defense contractor. I borrowed a Digital Storage Oscilloscope from work and connected it to the ECM's 5V rail. Cranked the engine, then looked at the scope - as the engine was hitting compression, the starter was loading down the ECM's 12V supply to below 5V in super-quick downward "spikes". The 5V regulator was therefore shutting down and forcing the ECM to reset. As it was resetting, it was losing spark timing and so never got it right to fire the engine. Took apart the ECM. Found a few capacitors with bad ESR ("Equivalent Series Resistance") caused by capacitor age - the capacitors were no longer capable of dumping their charge fast enough to smooth out normal transients caused by the starter hitting a compression stroke. Got good replacement capacitors from a reputable electronics supplier (do NOT buy capacitors off Amazon, they will be counterfeits or old!) and soldered the new ones in place of the old ones. I think the Fiero was only a double-sided board, modern stuff is going to be a multilayer board and requires really good soldering skills, but it is do-able with minimal electronics tools and a steady hand. Also watch for corrosion from the liquid electrolyte in the capacitors leaking and eating the conductive traces on the board - you can fix this carefully in most cases, but it has to be done well or the engine could stall at a Very Bad Moment like merging onto a freeway or making a left turn. Hopped in, turned the key. The Iron Duke came right to life. Rock-solid on the 5V rail to the TPS. No more reset being asserted to the CPU chip. I kept up the habit of parking the car on hills for a while until I was confident that the problem was in fact, cured. @shango066 does electronics repairs and resurrections and covers an ECM/ECU repair right here: czcams.com/video/RUhvuCwVIl4/video.html Hope this helps someone keep their old EFI car or truck running.
Mosfets wear out as well i went through all of this with my 87 Ranger. The caps were replaced and it still would drop the back two cyl. Turned out the mosfet that drove the back two injectors was failing solder joints looked great. Replaced and its still running great love how simple first gen fuel injection is. My truck has 1.3 million miles on it everything fails after that much drive time.
I could be wrong, but I heard that GM ECUs of this era had no electrolytic capacitors. I don't know if they used tantalums or simply omitted them altogether. Most ECUs will run ok without their electrolytic caps, it's only when leaking electrolyte starts eating up traces that problems crop up.
Someone I knew had a Pontiac running a 2.5L. He was so proud that it was "a Tech4!" Yeah, that just means it has EFI. It sounded awful, but did the job. Seems the louder and rougher the Iron Duke was, the more reliable it turned out to be. At least the noise told you it -was- indeed running. Now, our 2015 Equinox has a (fairly) nice sounding 2.4 that makes 182hp. Big difference in technology.
Keep an eye on the fluids in that 2.4. They are known to become heavy oil drinkers before hitting 100k miles. There is actually more demand than supply for replacement engines mainly due to people not checking their oil. Nothing worse than seeing people put on a waiting list while being without transportation.
I've heard horrible things about the Equinox being severely under powered. Also, no shortage of them in my local U-pull-it yard. Does yours have turbo?
In my 89 S-10 2wd 5spd...that noisy bastard of a 4cyl was magnificent. I'll never forget plowing down the freeway to Grand Forks at 80mph and the lil S-10 was loaded to the gills with cargo and sounded like the Memphis Belle.
Having worked on these in the day, the primary source of noise is too much backlash between the cam and crank gears. Early on, replacement gears still had too much backlash and continued to make noise after replacement. Later a revised gear set hit the market and the engines were relatively quiet. The Iron Duke in rear drive cars had intake and exhaust on the same side as it was based on the 250 / 292 inline 6, this configuration continued on in boat and industrial applications ( like forklifts and generators ) expanding to 3 Liters . In fact, the 3 L was available in the GM performance parts catalog as a 3 L Super Duty as some were road raced in Fieros. And. . . the company Blueprint Engines still builds a version of the Iron duke for industrial applications. There is even a prototype with a GM LS V8 head. Front drive cars got a cross flow head and later a tubular exhaust manifold. These tube manifolds tended to crack where all of the cylinders joined together however there are easily welded with a MIG welder running regular mild steel wire. ( I had a spare cylinder head at the ready to use as a welding fixture ) The N cars used a shorter version of the " Tech 4 " as under hood width was at a premium.
The engine that was based off the 250/292 six was never called an iron duke. That was the Chevy II 4-cylinder which was actually based off the Chevy 194 six. Only the Pontiac designed engine is called the iron duke.
@@Cream_of_sum_yung_gai The Iron Duke / Tech 4 were not clean sheet designs by Pontiac, all they did is take the non cross flow headed 4 cyl and designed a cross flow head as well as making it front drive capable. ( Side mounted water pump , smaller bell housing ) The timing cover gasket ( all the way up to the N cars) is the same as a Chevy 250 / 292 inline 6 . The last " real " Pontiac engine was the 265 / 301 V8 that went away in 1981 ish so Pontiac engine engineers didn't have much to do so I'm betting this is why the 4 cyl was attributed to Pontiac. All the other divisions still had their native engines going or were busy working on moving to corporate engines. Calling any of the 3 four cylinder engines Iron Duke is generic enough that anyone in the biz knows what someone is talking about.
@@bobroberts2371iron duke has the distributor at the flywheel end of the block, Chevy II has it at the front. Head bolt and bore spacing is also different.
Many of the old post office trucks still on the road have the mid 80's GM S10 chassis with the 2.5 engine. After almost 40 years and several hundred thousand miles they are still running.
Was never a huge fan of the Iron Duke to drive, but can’t deny it was an absolute tank of an engine. I absolutely will miss it when they phase out these old mail trucks. I can always hear it coming long before I see it, and half the time can tell the mail went even if I’m no where near a window lol Will be a sad day when they park the last of these
we had a 91 Grand AM LE 2 door coupe with this motor. It was quiet and smooth. However, when we owned it, I was a teen age boy with my new to me license and would drive it very hard. It got noisy after a while but never broke. I think it was those timing gears that just started clattering. It had good pick up for a small car. It would easily spin the 14" pontiac alloy wheels with p205 65 size tires. Once I drove it from San Francisco to LA averaging 95 - 100 mph. I made it in 3:40 min non stop. Car took it like a champ.
The thin stamped steel rocker arms also added to the clatter on the 2.5 and the 2.0 in the Cavaliers. Adam is right that if you didn’t beat on them they could last pretty well if not gracefully
Stamped rockers are alright provided the following things are done. 1) Thick enough steel is used. 2) A proper punch and die maintenance program is set-up and followed. This makes sure you have the proper radius in the bearing area, the correct radius on the tip that rides against the valve. And a properly formed pocket for the pushrod. Plus all these things have to be on their proper relationship. 3) The rockers should be run through a heat treatment process and properly tempered. 4) The lubrication system needs to pump enough oil up through the pushrod and the rocker arm oil hole. I worked in a facility that produced stamped rocker arms along with other stampings. We had one die maker all he did every day was take care of the punches and dies for ru ocker arms. One press, that's all it did. The most fascinating thing about their production was a small press, maybe 5 ton, that punched the oil hole in the pushrod seat. About 1/16th in diameter. Straight through steel 1/8th thick.
Not a rocker arm issue. Most of the noise comes from too much backlash between the cam and crank gears. There was an updated gear set with minimal backlash that took most of the noise away.
When I was in my high school, a friend of mine had a Pontiac firebird that had the iron duke teamed to a 5 speed. It was slower than death, loud, and crude but never broke down.
That would be the worst application of the Iron Duke. For some reason, GM put these in cars without a temp gauge, and when they overheated it caused a lot of fires in these cars. Also, people revved these engines higher because it was a sports car. They didn't live too long in Fieros. That being said, I'd love to have one.
This is a very familiar sound. Their were a lot of them, back when we all used to buy North American cars. A video on the quad-4 engine would be interesting. I remember many people were left stranded by GM with that engine.
I had an 83 LeBaron Convertible with the 2.6L "Astron" engine as it was called by Mitsubishi. Great engine, very smooth, not very powerful (92hp I believe), but you never really noticed it in that car, it pulled it along quite well. Compared to the Chrysler 2.2L engine, it was silent since the 2.2L as it aged started to sound like the iron duke engines, but they are still reliable engines.
AFAIK Mitsubishi pioneered the use of balance shafts, and back then was the only automaker using them. At some point they licensed it to Porsche for use in Porsche’s 3L 4-cylinder engine.
I remember all those Bitsumishi engines having nice sound and performance compared to the 2.2L/2.5L K-car engines, but they did get to be known for oil burning and blown head gaskets. Of course, the 2.2L K-engine will blow a cylinder-to-water-jacket hole into the head gasket pretty quickly if you overheat it. But the 2.6L Mitsubishi engines (and the Mitsu V6) didn't seem to last as long, at least around here. We go from -40C to +30C from winter to summer, so imagine Ottawa, Canada as being Detroit's climate but colder. I think the heat cycling from -40C to thermostat temp was harder on the Mitsus than the Mopars.
Boy, that is a key sound of the 1980s and it was everywhere. The weird thing is that common sound of the Iron Duke made my Calais’s Quad4 feel and sound like a finely honed Swiss watch!
The Quad 4 was a relatively smooth engine and when equipped in the right car produced exactly twice the hp of the Iron Duke. Quad 4s get a bad rep, but I had one in a 1989 Calais and it was pretty stellar. The early ones were trouble prone, but the later ones were sorted out.
@@paulwindisch1423 I loved my ‘90 Calais with the Quad4. It was seriously quick for the era. I could easily keep up with 3 series Bimmers and Saabs. My only complaint with the car was I wish it had 4th cog In transmission. Otherwise, nice light car with a people engine.
For sure! Out family had a 1984 citation, manual transmission, and 1985 celebrity wagon, automatic with iron Duke power. Pretty coarse and noisy! But we were fortunate, both vehicles and engines were very reliable and we’re still going strong at 250,000 miles when we finally traded them off. Both engines were still healthy, neither needed any internal engine work at all. the cars were wearing out.
It's funny you mentioned the run-on issue. We had an Iron Duke in the first year 1985 GMC Safari. Darn thing had an annoying habit of sitting and chugging well after you had removed the key and walked away from it. It would eventually kinda rev up slightly and then finally shut down. We replaced the carburetor twice and never did eliminate the problem. Gotta love it!
Yeah, the TBI EFI Iron Dukes can't do that as fuel supply is gone. TBI injector is triggered by ignition pulses. Distributor, ECM and fuel pump are all off with the key. I guess the trucks didn't have TBI by 1985 in all markets. Almost any carbureted engine can do this, but the Iron Duke was more prone to it than a lot of other engines. As long as the engine is still spinning, the fuel pump is still filling the float bowl in the carb, and something in the combustion chamber is taking the place of the spark. If you try hard enough, you could probably set up an Iron Duke with a carb to run (badly) until the fuel tank was empty. This is a classic dieseling problem - check your plugs. You will likely find that your plugs are fouled with fuel (too rich) causing carbon deposits to form in the less-than-ideal combustion chambers. Get your air/fuel correct, get your ignition timing right, make sure it's coming up to thermostat temperature on every drive, and the problem will likely go away fairly quickly as you burn off the carbon deposits. Casting flaws in heads or pistons could theoretically cause this too, and they will NOT burn off. Also, make sure your spark plugs are the right heat range, a hot ground strap can cause dieseling.
LOL.... also, check evap system, if it's full of fuel, that might cause an EFI Iron Duke to diesel, but you'd still have to have carbon deposits, casting flaws, or grossly bad heat range plugs to do this. Your Check Engine light would have been on for months for the carbon deposits to get bad enough.
Here’s how to not have it run on. Do this every hot shutdown. With engine running, put transmission in drive. With left foot on brake, right foot hovering over gas pedal. Turn key to “off” (not lock) turn steering wheel (try to) and give it gas. The slight load of the transmission, and of the power steering pump, will be enough to help it shut off instantly. No more embarrassing run on/dieseling.
Dieseling was not a new problem - I recall as a little kid my parents borrowing the '67 Chevelle of a friend who acquired it from their retired father, and that basic Chevy (probably its 307 V8, maybe?) surprised all of us when it ran on after my mom shut it off. Just think, this was a '67 that predated any of the emissions attachments that were so often blamed for such issues in the '73-'74 spaghetti-covered engines with air pumps, etc., of the pre-catalytic converter era. Maybe it was the Sunoco "Economy 190" low-octane gasoline we pumped into it?
Netherlands, early eighties: at a very young age, I bought a pristine light blue '77 Monza 2+2, 2.5 aut. from an elderly woman. It had run about 40K mls.. It looked great, so I loved it. Speed limits in Holland prevented me from ever over-revving it. Nonetheless it developped a nasty cold start with rattling hydraulic valve adjusters. Otherwise it ran well and it was quite torque (in comparison to small European cars). I vividly remember it shaking of it's radiator-hose several times. The shaking was so bad that even the radiator pipe broke a few times. My next car was a V6 Capri, then I realised what a sorry engine it really had been ...
@@martinliehs2513 It's styling still holds up. It looked even better than the comparable Opel Manta. Only, because of the Vega underpinnings, it was a wee bit to narrow.
@@martinliehs2513 Having owned a Monza Spyder and a 3rd gen Camaro, I agree! Even the rear suspension of the Camaro looked like the Monza's! Lots of engine choices in the Monza, depending on the year and area emission requirements, in addition to the 4 cyl, you could get a 3.2 or 3.8 Buick V6, or a 4.3, 5.0 or 5.7L V8!
MerCruiser also used a large number of these engines for marine applications. Various other equipment manufacturers also used this powerplant. FYI, the composite cam gear actually quieted the engine down by quite a few decibels. This is why GM went with the composite gear in the first place. As a side note, I think the vast majority of the noise this engine produced was related to the piston skirt length and the later models having a roller valvetrain. I think GM went roller with this model in the mid 1980s. 1985ish?
I used to be able to recognize that sound from a block away. Rude crude and ready to cruise. I love the one in my 86 Calais. Part of it's character. Sounds like a tractor. Trimmed like a 98.
I have an 87 iron duke that lost spark on cylinder 1 and 4. Do you happen to know the official method of accessing the distributor (on yours) or the coil pack on mine? I can only figure that you have to remove the intake manifold.
@@johnmaki3046 I always took those attributes [negatives? not for me.] of the Iron Duke as part of it's character. There have been three in my family. Two I have owned personally. Would love to have anything with it, perhaps an S 10. Or an AMC Concord. That would be a scream.
I remember it well. My grandmother’s 1987 Oldsmobile Cutlass Ciera that she bought new & owned it until the day she died in 1999. had the 2.5 Iron Duke 4-cylinder engine and 3-speed automatic transmission. It was a good car & reliable, but was definitely underpowered especially when the air conditioning was being run in the summer time. It was definitely more reliable than her 1982 Buick Skylark with a carbureted V-6 that it replaced.
I remember the Iron Duke inline 4's being rough running and course. A person who was used to a smooth and powerful big-block Oldsmobile or Buick would often choose a Toyota Camry or Honda Accord over a GM product of the era. In its defense, the Chrysler "K" cars were equally bad or worse. Truly a sad era for the American automobile industry. The US manufacturers never regained the dominance they once enjoyed.
The Mopar 2.2/2.5L K-car engine was clanky and noisy too, none of the gear growl of the Iron Duke because of the OHC timing belt. I like the Mopar 2.2L, after 1984 or so they really had the bugs worked out of it pretty well - just don't let it overheat or you will be needing machine work on the head. I am really glad GM didn't put something similar like the Cavalier engine into the Fiero, the all-iron Iron Duke tolerated overheating pretty well and until you learned the tricks to burping the Fiero's unusual cooling system, you'd see the temperature gauge do some pretty wild things which would have killed the Cavalier motor or the Mopar 2.2.
@@21Piloteer I had the same and I remember the GROW from the engine when I drove it uphill or from a stop light when fully loaded. By the way, I bought it used for a deal and it had a 4 speed manual transmission and a bench seat in the front. The stick shift was mounted on the floor and came up and over the middle of the front bench. Needless to say, no one could sit there. I only had it for about a year but it did hold up fairly well.
In the 1980s My girlfriend had the 2.5 in her Cavalier. I spent one afternoon trying various shims to quiet the starter noise, with little Improvement. The car ran strong for almost 200,000 mi.
I agree that the engine’s sound is fairly crude ..and am reminded of that daily as the mail truck comes by… but I’d submit that the 2.3 liter aluminum block engine in the early ( pre Dura-Built 140) Vega was cruder.. especially at idle.
I personally love the sound of these engines, but then again, it's my childhood and very recognizable to me from when I was really young. We had a 1986 Oldsmobile Cutlass Ciera with one of these engines in it and it was probably the most comfortable car I ever sat in.
I liked the sound too... Lol. It was the complete opposite of a Honda engine. What the Iron Duke did have going for it, was good fuel economy. And that was a good thing in the 1980's.
Here's my list (since Adam won't do a video): GM Best: Alfred Sloan GM Worst: Roger Smith, Mary Bara (tie) Ford Best: Donald Peterson Ford Worst: Jacques Nasser Chrysler Best: Lee Iaccoa Chrysler Worst: Lynn Townsend AMC/Rambler Best: George Romney AMC/Rambler Worst: Roy Abernethy
Crude but admirable. That's the best I can describe the Iron Duke. My sister had one in a 1986 Grand Am (loved that car!). It went 178k miles... 😊. You forgot to mention that this engine replaced the Chevrolet Vega engine for not being reliable. So this Duke was a HUGE improvement there... Lol. With that being said, the QUAD 4 was another bad 4 cylinder from GM. You can't hardly find those anywhere.., so the Iron Duke isn't really that bad.
I bought a pristine 82 olds omega 2 door with the iron duke in 1995 from a little old lady, had less than 50k miles. Needless to say, she had never had an oil change done. I changed all fluids but it still spun a Rod and main bearing within a month of purchase. I had to pull it and completely rebuild it. It lasted me from 1995 to 2005 and still ran great when I gave it away. If I remember correctly the cost of internals was cheap, It used Chevy 350 pistons and rods and Rod and main bearings. The phonetic gear was never a problem for me. I had the single fuel injector fail twice(TBI). Also the engine top Mount shock absorber(from the engine bracket to the radiator core support) would wear out, and would cause extra noise from the engine bay. It was a very reliable engine once I redid it
Actually it had the same pistons and rods as the Pontiac 301 V8, designed at the same time, which had the same 4" bore and 3" stroke...the Chevy 350 had the same 4" bore but I assume a different pin location due to the longer stroke & shorter rods.
Even under warranty the timing gears would make all kinds of noises!! Some sounded like rod knocks!! The GM techs got good at poping out those cam gears in the frames without many problems!! At the time where I worked was a triple franchise. Volkswagen, Pontiac, and the beautiful Yugo!! Hahaha. We use to call them.... YuDontGo!! We were rebuilding whole Yugo engines before 15000 miles!! What a sad company!! 😊 Yugo engines got real noisey as the camshafts rounded off and the pistons cracked to pieces!! Some would run to the dealer but most were towed!! Sad Yugoslavian Fiats!!
I had this in a nice silver 85 Olds Calais. I bought it at around 160K and was only able to put a few thousand more on it before the oil pressure would drop to zero on me after cruising on a highway. After that it developed a horrible sounding knock which someone told me was piston slap (could have been rod bearing knock). I drove it that way for a while more and yes the knock on top of the other accurately described sounds was embarrassing. My friends loved my car and it always got compliments (esp the interior), but they laughed at the engine. I sold the car after it happened the second time to someone who was going to rebuild it and he tried to drive it home that way (no oil pressure at all) and of course, blew it up. One thing I noticed about these engine is they were actually one of the best sounding 4 bangers I've ever heard with a nice turbo or similar muffler. The truck version that was in the S10 and mail trucks was a heavy duty version with a better block and crank. If you wanted to hop up this engine in your GM car, it was almost mandatory to get one out of a truck and start from there, and it was best not to go over 150 hp.
Did you ever need to service the distributor on that car? What was even the official method of accessing it in the transversely mounted iron dukes? Removing the intake manifold?
Have a 89. Grand Am... 2.5 automatic... It was a rental car, so the maintenance was ok, before I bought it. It's been over 30 years now. It still runs great. I'm retired mechanic,so I do my own repairs,and service. Minor issues.... Grand kids, and Great Grandkids... They all love driving it.
My first car was an '89 Buick Skylark with the Iron Duke. That thing chucked a piece of its oil pump balance weights through the side of the block, then (after it was repaired creatively) proceeded to drive another 13k until it blew a head gasket in the hot Phoenix summer at 101k. Still have the car and plan to swap in a L67 S/C 3800, a much better sounding and performing power plant imo.
I got a a 1986 GMC s15 bare bones base truck hand me down from my older brother. Iron duke, 4 speed manual, no power steering or brakes. I was 17 and it was a simple truck for a simple time in my life. I had so many adventures in that truck.
The iron duke was also a popular marine engine as well. I do recall the Mercury version did upgrade the Cam timing situation, probably OMC as well. Pretty bullit proof. Remember in a boat, the engine is at near peak revs simulating going up a hill floored going 80 MPH in a car, sometimes for hours at a time.
Yeah, I was often amazed how those 2.4L 4cylinder chevy engines held up in the stern drive application as well, even in the salt water. But, were they actually the iron duke engines?
There was the car version, the HD truck version in the S10 and mail trucks and then there was a race version you could order. Pretty sure it was one of the HD blocks and cranks. The race version was aluminum and could handle multiple hundreds of horsepower with turbos or nitrous (which is no big deal these days I guess).
@@steveoh9838 Yeah, I realize these engines were made by chevy and bought through GM, but I don't think they were the iron duke variants... Nonetheless, they proved to be pretty rugged in a most brutal application
The most crude sounding engine we had was a 1.8 in a Buick Skyhawk. The two nicest sounding engines were a mid 80's Ford 302 V8 and a mid 90's Toyota 3.0 V6.
Mopar slant 6 always had a certain noise to it, though I think it was just the valve train. Also too, those things were on the road for so long they seemed louder because they were from a bygone era.
The Slant 6 used solid lifters until the 80's, and I would imagine that nobody ever took their Valiant in for a valve adjustment! Besides, they were so reliable, all you had to do was add oil and drive it.
18 years ago (to the day), I got a free 1991 Calais. It had 141K on the clock and was in fantastic condition. The 2.5L had low compression on #4 and burned a lot of oil. I had recently purchased a house out of town and the 34-mile round trip to work was starting to hurt the wallet as at the time I was driving a huge crew cab Ford pickup with big tires. This car, even with the smoke and misfire was a blessing. At 146K, I decided to rebuild the short block. The EGR valve had failed and allowed detonation to kill the #4 piston crown (broken rings). I had the block bored and assembled the engine with nothing more than new pistons, rings, bearings, and gaskets. It's a timing chain/roller lifter engine so I reused that stuff. About 500 miles later, one of the balance shaft housing bores decided to get loose and thankfully at the time a new unit was available. The engine was full of aluminum particles but I kept running it. Technically, I never even had to pay for the $850 "rebuild". As it was an abandoned car, and the previous owner was long gone, the $800 I found in the glove box six months after putting the "new" engine in means the car paid for itself! I have done nothing but oil chamges at 3-4K mile intervals, one transmission fluid flush (125C), one set of front brake pads, three windshields, and four crankshaft position sensors within the 298500 miles. I guess I put new ball joints in it about 3 weeks ago because safety.....the left one was BAD. It still has the orginal transmission, water pump, wheel bearings, cylinder head, and suspension. It sounds like a small industrial indirect-injected diesel at idle and burns about a quart of oil every 1500 miles, but it's been a damn reliable car and still manages 25-26 MPG. I only drive it from November to May because the AC quit years ago and the stupid slotted plastic tape window regulators have broken a few times and no decent (read: US-made) replacements exist. I put snow tires on it and it goes anywhere I need to go until the first of May when I change the oil and park it for 6 months. I am a diehard Ford guy and would NEVER spend money to buy a GM product. However, since this car was given to me, I have become super-impressed. It's no sports car, but it's treated me well and when the Iron Duke dies, I will try to find another.
A big part of the harshness is it's a large displacement 4 cylinder with a camshaft that turns in the opposite direction of the crank because of the gear to gear timing. I've built a couple fully. Going as far as to balance the pistons and rods weight actually helped make the last one I rebuilt sound less horrible and more like just another engine.
My all time favourite: The Ford HCS I4 Engine. Not sure if it was ever sold on the US market. Anyway, the rattling was so distinctive that you could specify the type of car just by the noise.
Terrific piece on the ole Duke. Along with at least one other video you’ve done on this engine I’ve learned a lot about it. Oh, and still like your Omega-lots of 80’s memories come flooding back when I see that car 😊
The Iron Duke in my Astro van went for 335,000 miles when I sold it, running great. The new owner totaled the vehicle in 6 months, but engine was fine. Slow as a tractor trailer on the highway though.
The 2.5 always starts in the coldest weather. My mom's started back like 85' negative 25 while my dads Caddy, and his friend's Honda's Toyota's and other cars wouldn't my mom would also make fun of them! That car was a 82' Citation was great to us we traded it in in 91'. We had a 88' Celebrity with 2.5 wagon that lasted till 200k miles never broke down, I turned it into a dune buggy off roaded reverse slammed , 3:28 ran it without coolant until it slowed down ! I miss it can't find them now in the northeast.
The phenolic cam gear was used on the ford 300 i6 as well,they lasted pretty well, but I tore mine apart to replace it with a cast iron gear that will outlive me. I can see why the factory chose the phenolic ones though, as it sounds much like a tractor - works for me as I am happy with the reliability.
I had a 1987 S-10 for 11 years Iron Duke. Fiber gear failed at 125,000 had it towed to BES and they bored it.030 over and it was still running when I sold it to my brother in law.
For a company whose last name is "Motors" GM has a number of notably nasty four and six cylinder engines. The Iron Duke, definitely. The original Pontiac Tempest "Half-a-389" that sounded like a rock crusher. But the the piece de resistance has to be the "odd fire" original V6 that Buick developed. The car sounded like it was "missing" (because it really was).
I worked as a mechanic in the late '80s and saw dozens of those iron junk engines. Not the worst thing I've seen, but they were pretty bad. The biggest problem I remember was cracked heads.
They were distinctive sounding for sure, but that crashy starter sounded like they were made with warped flex plates. Couple months ago I had to get a 3 Cyl kubota diesel to move itself out of a situation with only one bolt in the starter, it didn’t even sound that bad 😄
For whatever reason, the sound of that Omega, which is identical to the sound my father's Citation used to make, just doesn't bother me; it's almost endearing. I've read that GM deliberately made the piston rods of the Iron Duke longer than those of the 2.3 L Vega engine, in response to complaints about that engine's secondary vibration, so you might do a comparison test with an original Vega, if you can find one. I do remember being bothered by some of GM's later 4 cylinder engines, particularly the 2.2 L engine in the Barretta, which was said to be related to the much despised 1.8 from the early J-cars. That engine made a booming that made the interior of the Barretta sound like the inside of a tuba; maybe GM's efforts to get more HP out of the same displacement led them to go with a noisier exhaust system. Some of the not-so-well balanced V6s of that era, particularly the 3.8 L engine in the 1993 Thunderbird also rubbed me the wrong way. It would be very interesting to see how a pre-1977 odd-firing Buick V6 stacks up against a modern engine, remembering that while odd-firing, that engine was also one of the only V6s that was perfectly balanced. Would it be ugly, or just strange? One engine that sounded like a metal chipper was the inline 5 they put into some of the early 2000s Chevrolet Colorado pickup trucks. There was nothing endearing about the sound of that thing, and no reason to think a 5 cylinder engine would ever sound good.
My dearly beloved neighbor had a Colorado that he inherited. Had multiple head & intake manifold gasket problems on a very low mileage pickup. After the 2nd failure he got rid of it & got an old square body pickup instead. Miss you Ray.
Its noisy, its slow, and its heavy, but its reliable to a fault. I had one in my 1988 Grand Am 5-speed, and it was great. Decent on fuel, although it leaked oil like crazy, but it never let me down. These things are almost agricultural in their design, sound, and power output. And those balance shafts, that was the only thing I ever had issues with in my Grand Am. They just let loose and lost the oil pump since its driven off of the balance shafts. Thankfully I was still able to source one from GM at the time (2005 or so) so I could replace it (which is easy) and keep going!
@@gregorymalchuk272 from underneath the car. the crank sensor is behind the coil pack/igntion control module and it fails quite often. Its not too terrible, but its a pain in the rear.
@@MichaelAStanhope I was looking at it from that angle, but some steering link or sway bar and a transmission mount keep me from being able to get an arm up there. Somebody else said that the recommended thing was to unbolt the dog bone motor mount, swing the engine forward by about 4 inches, and access it from the top. I lost spark on cylinders 1 and 4 on an 87 iron duke with distributorless ignition. I was suspecting a bad coil or bad ignition module. What problems does a failing crank position sensor cause? I have heard of it causing no spark, but would it cause this? I had heard that the crank position sensor is connected to the ignition module and actually comes out with it.
@@gregorymalchuk272 yeah, you have a failed coil. There are 2 coils on there, one for Cyls 1 & 4 and one for 2 & 3. One of them has failed. I would replace both of them to be safe. You can do it from the top if you take the torque strut mount off (dogbone). Not sure what care you are working on, but in my old Grand Am i found it easiest to get access from underneath the car. If the crank sensor goes out, you will get NO spark at all, as in the car won't run at all.
@@MichaelAStanhope Do you think it's the coil or the ignition module? They use a wasted spark system, so I measured both the coil secondaries through the spark plug leads and got 28000 ohms. Perhaps 10500 ohms for each lead and 7000 ohms for the coil secondary, which is exactly what the Haynes manual says. Do the coil primaries short or go open? Were the coils common failure items? I'm more suspicious of the 36 year old power transistors in the ignition module. If it was easier to access I would be tempted to swap the coil position and see if now cylinders 2 and 3 are dead or if it stays at 1 and 4. But the difficulty makes me want to replace everything. Another thing is that the V6 engines would get corrosion and lose the ground through the bottom of the ignition module to the bracket, is that a problem on the iron duke?
Totally agree Adam!!! We had one in a 1981 AMC Spirit and a 1986 Olds Cutlass Ciera with the Iron Duke. Both ran great but couldn’t stand either of them so noisy and unrefined. The whole dashboard on the Ciera would shake violently at idle! It was so ridiculous. I’m much preferred the AMC 258 in-line 6. Yes my post office still uses them and I always know when the mail is here when I can hear the Iron Duke pulling away from the house! lol!!
I have owned a lot of tech 4 powered cars. I still have 2. My friends have always said that they sound like a sewing machine. I haven't lost any timing gear teeth on any of the 20 plus tech 4 powered cars that I have owned. Even my 230,000 mile 6000 that I still own has original gears. Unfortunately, my friend took the gears out on his mom's mint 1987 Grand Am (in 1995) He was in the process of trying to do a Rockford when they let loose.
Do you happen to know the officially prescribed method of accessing the distributor or distributorless coil packs/ignition module on the transversely mounted iron dukes? Does it involve the removal of the intake manifold?
@@gregorymalchuk272 I do recall it being really tight back there. The steering rack and transaxle are partially blocking the access from below. Access is tight from above because of the intake manifold like you said. I had to replace the pickup coil and module which required the removal of the distributor. I removed the front upper torque strut and rocked the engine forward. It was tight but manageable.
@@dueljet Yep. Some steering component or sway bar link and a transmission mount block access from below. I lost spark on cylinders 1 and 4 in an 87 iron duke and am suspecting a bad coil or ignition module, but am struggling to figure out how to access them. It's a shame, because the coil packs on the V6s were trivially easy to access.
@@dueljet LOL.... That was the ONE THING on the Fiero Iron Dukes that was relatively easy to get at, if I recall. The labor manual for the Fiero 2M4 was basically drop the entire rear cradle for anything. When you take out the dog bone and find a bottle jack which will work sideways you can get a lot done without having to do a four-wheel alignment across all 6 balljoints and all 8 tie-rod ends in that thing. DO NOT trust the old camshaft gears. They can let go at any time. At least it's not an interference engine, so while it could strand you (usually on startup) you're not likely to have malice in the combustion palace to quote Eric from I Do Cars. A friend who also had a Fiero 2M4 somehow managed to change the timing gears without pulling the engine - I do not know how, because the large gear is pressed onto the camshaft. You CAN remove and replace an Iron Duke from the top of a Fiero, I got it down to about 8 hours total to remove and replace it in the over 300,000km I put on that car in the years I had it. After working on my friend's Fiero 2M6 a few times, I was really glad mine was a 2M4.... It wasn't a fast car, and it was seriously hard to work on, but it was such a fun and great little car when you got it working properly.
The iron duke was actually a very popular and very reliable engine. It was installed in FWD cars. RWD and 4x4 jeeps and many other applications. The only real design flaw was the plastic toothed timing gear. Other than that a pretty reliable rig. Im a retired GM tech with 40 yesrs in the service bay.
GM also used a nylon camshaft gear with the timing chain in the late 70s V8s, they also stripped off after 100k miles. Luckily with the deep dished low compression pistons it wouldn't hurt anything and you could just put a good all steel timing set on for $40 and be back on the road. Dodge 2.5 4 cylinders also sounded terrible in that era, they have fuel saving short skirt pitons that developed bad piston slap in a few years. The dealer I worked at would get those cars for $400 or less at auction, spend $200 on a headgasket, 4 new pistons and rings and put em up for $2495 to $2995 sounding like a new car.
when I was young I bought a 1985 Buick Sommerset Regal that needed an engine. I swapped in a junkyard engine/trans and drove it for years. My 2 favorite things about it were the comfortable seats and how amazing it drove in snow. Also the thermostat was super easy to change as it was right under the radiator cap- no tools needed!
Fuel sipping , pocket pleasing front wheel drive Omega by Oldsmobile... we had one built for you! Omega! Oldsmobile....I remember this engine. I remember putting this engine in so many GM cars. I recall it was even offered in Firebird and Camaro at one point. What about Quad 4? It was a high tech 4 cylinder engine. The interesting that the 4 cylinders are more powerful and turbo charged too. I liked the fact you mentioned the GM Brazil engine. Thank you once again Adam.
He does great reviews. I want him to review the Quad 4. I drove one in a Grand Am in the late 80's. I took it back to the dealership 😂. That thing was rough.
@@keithjackson286 I would like to hear what he has to say about the Quad 4 too. He does have great videos. I never called this engine the "Iron Duke".. I always called it the Tech IV 4 cylinder. My uncle had a Pontiac Grand Am that had this engine. I had a friend that had a Buick Skylark that had this engine. I know two people who had a Oldsmobile Cutlass Calais with this engine. I recall seeing loaded Oldsmobile Cieras and Pontiac 6000's with this engine. You could hear anyone coming with any GM car that had this engine. The mail trucks are still in service as he says.
I had an ‘87 that went 310,000mi and knocked from one cyl. Best to have a switch to override the 235’F when the fan comes on. That’s too hot. I just shorted out the CTS with a switch. Shut switch off and the SES light went back off.
I had a 1974 Mustang that I purchased new. 2.8L V6 engine with solid lifters, nylon timing gear. The engine was the same engine as used in Europe, from the Cologne, Germany Engine Plant. The engine sounded great and was very “healthy” when coupled with the manual 4 speed trans. Night and day difference compared to this engine.
My parents had that engine in their Pinto wagon.You could pass anything any where & still get 27mpg with an automatic! When it came to ice & snow however you would be better off & safer riding one of our thoroughbreds!
@@frederickbooth7970 Wow, had the completely opposite experience with my parents '75 Pinto wagon and that engine - loud, chattering from its first day off the Ford dealer's lot, and all that extra engine provided maybe average 18 MPG and no "pickup" as they used to say. But compared to how my dad described a guy in his car pool's Pinto Runabout with standard 4-cylinder and air conditioning on, that V6 did sound a little less strained.
@@70sleftover Our V6 Pinto wagon had no a/c so that may have helped on power & speed . We also never hauled anything but my dad & myself most of the time when commuting back & forth to work. Because of the Pinto`s VERY dangerous handling in ANY kind of frozen precip. we got rid of it after having it one year & went to a 1976 Volare` wagon instead. Much safer & most of the time we were able to get 22mpg on the Hwy with the old slant 225 straight 6. Absolutely gutless engine above 40 mph though when wanting to pass motor homes or trailers!
Like the old-school Explorer 4.0 V6, including the OHC variants, (which were likely from sometime in the late-1990s to discontinuation) which I remember, because I used to be in contact of a person who had a 2002 Ford Explorer Sport Trac and it was still soldering along with at least about 260,000 miles. But, it sounded like it was time to change the chains and guides, because it sounded like a bicycle at idle, LOL. In 2016, it seemed fine, still, despite the top console already being dead for a while (can't see temperature of outside or clock, IIRC)
Back in high school, one of my shop classmates had a blue 1986 Firebird with the Iron Duke & backed by an automatic transmission ( final year the Iron Duke was offered in the " F " body ). I went to work. Painted it black. Put a gold " Screaming Chicken " on the hood. Put gold Trans Am flares & Trans Am smoked tailights on it. Installed a set of mid-1980s Trans Am wheels shod with B.F. Goodrich T/A raised white letter tires. On the rear bumper, I stenciled in gold... " Looks Fast! "
This engine is one of the main reasons why buyers fell in love with the Japanese 4 cylinder engines. They were better in every way imaginable. The 2.8 V6 was a MUCH better choice if it was an available option. I have a 2.8 with almost 225k in a 1987 Fiero that has never given me any problems at all and other than a starter and alternator has never needed a major repair. It also still gets 23mpg.
We went 233,000 miles in our 84 S10 before having to re-bore & have new pistons/ rings. 280,000 miles & still has original oil pump & crankshaft as well as rods too. Could not find a new oil pump with correct pressure so ended up using original as the pressure is correct at idle & hwy speed.
I had a girlfriend who had a Buick Century with an iron duke. It was loud and junky sounding but very reliable. I currently have a little S10 in my fleet with a 2.2 that reminds me of the iron duke. It's more modern but still has an unrefined "agricultural" tractor sound to it.
I agree, they are the most crude sounding engines that GM ever made. They were good and reliable engines though, particularly the '87-up with distributor-less ignition. They were fun to drive too, if you were a young teenager that had the pedal to the floor everywhere you went. 2.5 liters of raw horsepower, haha.
I remember trying to do a brake-burn with my father's Citation and it was like trying to dribble a dead cat. There was simply no high end whatsoever. But, if you let the transmission take it from idle, it was solidly in slow-but-bearable territory: never exciting, but never really agonizing either.
Perhaps you may have the answer I'm looking for! Do you happen to know the officially prescribed method of accessing the distributor or distributorless coil packs/ignition module on the transversely mounted iron dukes? Does it involve the removal of the intake manifold? I have lost spark on cylinders 1 and 4 and am suspecting either a bad coil or bad ignition module, but don't see how to access the coils. It's a shame, because on the V6s, the coil packs and ignition module beneath were easily accessible on the front passenger side.
As a late teenager & early 20`s I had the real life horsepower from thoroughbreds! Lots of raw power up to about 40mph! No seat belts or airbags. Had to hang on tight! Explains why I never got in trouble with high performance cars such as the police cars I later sometimes drove for the GM dealership later on when delivering them back to the station servicing.
Had a 2.5 in my '87 S 10....never left me stranded in over 100k miles. Although I was always changing the oil because the pan only held 3 quarts. Fun little truck
When I was a mechanic at a Chevrolet/ Oldsmobile dealership in the 1970s, we had the precursor to the " iron duke". It was the same engine except it had aluminum cylinders! That one made some memorable sounds as well :) The fix was to fit cast iron cylinder sleeves in those aluminum blocks, viola, the Iron Duke.
Hi Adam! Great video! I actually enjoy hearing the occasional tech 4 out in the wild ( or our LLV that delivers my mail) as it brings back a lot of great memories. I guess having grown up in the '80s/ '90s caused this. I have pointed out to you via other posts that the engine did have some advanced features like a roller cam, stainless tubular exhaust manifold, TBI, and a nifty flow-through head design. Not amazing by today's standards, but it is unfair to hold the engine to contemporary standards. I think that your calculator watch is cool, but totally weak and useless when compared to your smartphone. We can probably agree that my previous statement is an unfair and silly comparison. The same goes for the tech 4/ Iron Duke. I worked at a Buick Pontiac dealership for several years in the mid 1990s. I was a teenager at the time and had the privilege of working with a lot of seasoned and talented guys. None of them were overly critical of the engine. The old series 1 3.8 liters were rough running and a little crude too. The old 2.8 had issues too (Intake gaskets, etc).
My 2.8 came with loose intake manifold bolts but with the help of a Snap On flex socket I was able to torque them to service manual specifications and no more problem. That thing had dual valve springs!
The 2.8L was a great engine in the smaller X-cars, but when GM put in the S,T pickups/Blazer/Jimmy they won't so great. Besides the head gasket issues they would take out cranks and very hard to work on because of the space in the engine bays.. spaghetti vacuum lines, feedback carbs, marginal electronics and list goes on.
A friend used to have one of those small S 10 type trucks and got good service but it had a larger V6 that I think was based on one of the smallblock V8s. I did at a point with my Citation managed to get the headbolts to turn a bit tighter,to the factory torque specification. Also had the car rigged with a switch under the dash that when turned on made the electric radiator fan run constant. When sitting in traffic or something that would make the temperature gauge rise I would turn that switch on. I got over a 100,000. miles on it by the time I got rid of it,mostly because of floorpan rust. By the time the S 10 and small Blazer matured with the larger V6 it seemed to have become a pretty decent vehicle but of course whenever GM got something perfected seemed to have been the time that they discontinued it. @@michaelmurphy6869
@@ButterfatFarms no, but they were not always looking at vehicles of similar price. As I have stated before, in addition to electronic fuel injection, the engines also had roller cams and stainless steel tubular exhaust manifolds. The gear drive was also better than a belt or chain in many respects (not all). They were also BMW jags like the boys at Motor Week. I believe the contemporary term is fanboys. I think it was all too easy to rip on the general whenever convenient. I have owned over a dozen tech 4 powered vehicles and none of them have had a catastrophic failure.
I remember being 18 years old and working at a car lot in 1990 and a beautiful and loaded 1988 Pontiac Grand Am with around 20K got traded in with that 2.5 Iron Duke. I asked my dad (who was an auto mechanic) to take a look at it because I was thinking about buying it. The instant my dad started the car and it ran for about 10 seconds, he said nope you aren't buying this car. He couldn't believe how loud that engine was (and the starter) and he said it sounded like it was about to come apart. I ended up buying a new 1990 Toyota Celica instead.
Ive driven a few different vehicles with that motor in my younger days i noticed that in all of them, the throttle pedal was really stiff it always took a lot of foot pressure to press it down . Was that an intentional design feature for some reason? Like to keep people from trying to rev them up too fast?
Yes when the x cars came out, they rigged the throttle. Pressing the gas pedal about 1/4 to 1/3 of the way down gave you 90% throttle. This was to make the car seem fast on a test drive. “Wow, I’m barely pressing the throttle and the car’s flying! Not bad for a 4 cylinder!” is what they were hoping everyone would say. It was so bad that the throttle linkage would break/snap off in a few years. Chrysler did something similar with their 70s cordobas (etc.) gas gauge would barely move from full until tank was 1/2 full, then needle would plummet fast. “Wow, I borrowed this loaner, drove it all week, and the gas gauge didn’t even budge. This car is good on gas!”
My first car which was passed through my family was an 89 Pontiac grand am with that engine. Then a 91 chevy s10. I'll never forget them. Years later I found a cutlass Calais 1990 two door! Great memories and ill never forget that sound. A loud torquey little engine!!
The name is all you need to know. The Iron Duke was a bullet proof engine! I guess if you had a lot of money you could buy a car with a quieter engine. But for the price it had no problem with the noise. Ran mine for 200k and was still running!
Any engine that refuses to stop running seemingly FOREVER sounds good to me. Wasn't made for racing, low power was a key factor in its durability. Gear driven cam was another. In front wheel drive it was nearly impossible to remove the oil filter on a neglected one in a FWD, but the Iron Duke would still always get you there. What's embarrassing about that?
About a year after I got to my first duty station (1983, Wright-Patterson AFB) the local car dealers got together and were allowed to come on base to show off their new cars. At the time I was interested in a new car and the dealer really talked up this nice metallic gray Camaro. We took it for a test drive and he said "floor it!"--I assumed it was a 2.8 V6 because it sounded throaty, the engine was giving all it had but we didn't seem to be going any faster. Popped the hood after the drive and there sat the "pride" of GM...the Iron Puke 4-banger, walked away even as the dealer was talking economy and "power."
I couldn't agree more! My first brand new car was a '86 Olds Calais with the tech 4. I wanted the 3.0 V6 but in hindsight maybe I dodged a bullet. Outside of how horrible it sounded the vibration was terrible. The spokes on the steering wheel in that era of Olds were low. The top of the wheel vibrated so horribly! It was irritating! Under warranty the head gasket blew due to over torqued head bolts. It leaked from the thermostat housing. The repair at the dealership was to goop it up with silicone. I eventually replaced the housing. Problem solved! I traded up for a '91 Quad 442. When was the last time you've seen one! The quad 4 was stellar! Wish I kept that one!
@@gregorymalchuk272 it was on the firewall side of the block. I never had to deal with it. I recall looking at it and thinking about how tough it would be to get to.
Noise and resonance from tubular exhaust that would glow red hot under load, the vi ration would snap the starter outside too, replaced a few cam gears on these in the Fiero by dropping engine down at an angle to slide the camshaft out! Easy to work on.
Remember it? Millions of people all across America hear it every day in the Grumman LLV aka the USPS Mail Truck! 30 years running and still being beat on between every mail box.
A company I worked for bought a iron Duke equipped Chevrolet Astro van, about 1989. I had the honor of driving it from the dealership. The gas pedal was mostly a volume control, stomp on it and it got louder but didn’t seem to accelerate any faster.
I could definitely see that. Even with the 2.8 that van wasn't very peppy. It wasn't until they put the 4.3 v6 in it did that van gain any real capable engine. That must have been a really low end, if rare Astro. I knew they made them. They probably didn't sell too many for that reason you made. I know that engine wasn't really powerful in my Cutlass wagon, I cant imagine a worse slug.
My parents had a 1986 Chevrolet Celebrity with the Iron Duke 2.5L I-4 ... I couldn't imagine that engine trying to lug around something as heavy as an Astro van.
GM "sound of power"
My parents had a 1988 Astro van, I remember reading the Haynes manual as a kid and wondering exactly how it was supposed to even move with the 2.5 liter engine. Ours had a 4.3 and it did just fine.
I thought they went too far with the iron duke Camaro, but jeez 😫
I had a 1984 Fiero with this engine. Leaked oil and sounded like a farm tractor. That said, never failed to start on the coldest New Hampshire winter. Totally trouble free. I actually liked the sound - that of brute force simplicity and reliability.
When I think back to the Iron duke days the first words that come to mind are "brute force".
👍
I have one myself and it sure isn't a "sporty" sound for a sporty car. That said it's okay as long as you remember what it is.
The slowest modern car I experienced was a Ford Fairmont station wagon with an inline six and automatic transmission,seems you could floor it and it just lackadaisically sort of moved along accelerating barely as fast as normal unhurried traffic-strange because that engine was larger than the Citation V6 but I had one of those loaded down with about half a ton of someone's mineral and rock collection and personal stuff (I was helping him move to a new place) and the loaded down Citation which with that load weighed more than the empty Fairmont still accelerated quite a bit faster. And that Citation was not as fast as my X 11.
My parent had a Pontiac 6000 with one. It ran. That’s the only thing positive I can say. I can hear my mail man 2 block away.
@@davidpowell3347 The Ford Fairymount looked like a car designed by someone that hated cars …
It's the sound that lets you know the mail has arrived.
Literally came here to say the same thing 😂
Same motor is in the Grumman llv😂
I can hear the mail carrier's vehicle a block away. It gives me time to walk out to the mailbox from the house. Thanks, GM!
Mail carriers used AMC engines in my neck of the woods
The engine sound might have been embarrassing, but the noise the starter made was downright frightening.
I think that car shared something called "5MT" starter with the 2.8 V6 and the Vega. I think base models only had 275 CCA battery from the factory,V6 models probably came with 350 CCA and there was an option for a 460 or 465 CCA battery in the V6,same battery that a pair of came in some of the Diesel vehicles.
Most of the noise was from cam / crank gear backlash. There was an updated gear set to fix this.
There are two great replies already. Also, Iron Dukes use starter shims to get pinion-to-flywheel clearance correct. If you don't shim it, you will have noise and eventual problems.
I always wished I could have bolted a Chrysler gear-reduction starter into my Fiero's Iron Duke. You start the Fiero with the sunroof open and the passenger will be startled.... "Wait.... Is the engine behind us??" LOL.... it got more fun when they asked what the buzzing noise was from between the car's seats.
Man, I miss that car. It wasn't fast, it was hard to work on, but it was fun and fuel efficient and had no problems holding 75+MPH from Michigan to Maine.
LOLOLOL
That’s anything but frightening.
Run a 2.4 or 2.5 on an open header.
Tractor on meth.
My college roommate bought a 88 S-10 with the 2.5 and a 5 speed, his first new vehicle. He drove it 498000 miles before he sold it. It ran at least another 5 years before it was sold again and never saw it again.
Noisy, but very reliable.
Oh yes, I remember it well, as it was very distinctive. As far as the worst sounding GM engine goes, I'd say it ties with the Oldsmobile 350 diesel. Not solely because the latter sounded like a diesel, but because it also sounded like something wasn't quite right under the hood of any car so equipped. And...my mail carriers still drive those Grumman USPS vehicles every day! As you'd once said...."GM engines run poorly longer than other cars run at all".
Just because you don't like the sound an engine makes does not mean it is running poorly. An engine is a large collection of rotating and reciprocating parts. It is going to make noise.
@@geraldscott4302 the GM V8s of the 60s and 70s were buttery smooth
@@geraldscott4302 Nonetheless, it does not inspire confidence. Of course, I voted with my checkbook and never purchased either one.
The " newer " LLV got what ever " modern " 4 cyl that the S-10 got .
My mother was once pulled over by a cop because of all the normal noise her 5.7 N diesel engine was making! The cop could find nothing wrong with the exhaust & so issued no ticket. He said it was the smelliest & filthiest most disgusting truck he had ever pulled over! At the time my mother`s 1978 Silverado C10 was still under warranty!
I remember that sound like it was yesterday. Growing up my neighbor owned an ‘81 Skylark Iron Duke…every winter morning I’d hear it starting, idling for 10 minutes, and accelerating away. During the same time his wife drove an ‘88 Celebrity Eurosport with the 2.8 MPFI V6 and the engine and exhaust note was impressive to me even by today’s standards.
Agree on the 2.8 exhaust note. My friend had a Chevy Beretta with that engine and the growl from the exhaust was impressive.
GM 60 degree V6s have an exhaust note they don’t deserve.
Ah, the Celebrity Urinalsport. That's one I haven't thought of in a while. My Fiero had the Iron Duke, but I remember the 2.8L V6 Fieros did have a nice sound too. I liked the Iron Duke a lot. It was hard enough to work on, I remember helping a friend fix his Fiero 2M6 and being really glad mine was the 2M4.
True on both counts.
@@Bartonovich52I believe any V6 could sing "I'm Popeye The Sailor Man" with its raspy growl.
I have to agree with you. These things have to be the crudest engines GM every built. I remember working on them back in the day we got a lot of these in for warranty making noise. One of things they would have us do is drill a small hole in one of the oil galley cup plugs. It was right behind the cam gear. This would allow more oil to lubricate the gear. At best this was a band aid fix. It did make the gear last longer. You are right the noise is generated from the cam gear interacting with the crank gear. The repairs we did did improve them a bit but they still vibrated pretty bad. The balance shafts where a God send. It smoothed these out a fair bit. Another issue with these is head bolt fractures. The head bolts from the factory where actually too hard and did not have enough stretch during thermal cycling of the engine. Over time they would break. The repair was to replace the head gasket obviously and with the head gasket you got a set of head bolts which where actually softer. The torque sequence was also changed to a torque to yield configuration. As you said these engine where reliable just very crude.
If anything, the phenolic gear would tend to dampen noise.
I found the noise was changeable for better or worse, by shimming the rockers.
Too much though, & it wouldn’t run right.
These ALWAYS sounded like CRAP, but so did MANY "G.M. classics"! They DID USUALLY "do the job", though!
I had a Duke in an '84 S10... unrefined it may have been but it was just a brilliant workaday mill! I live in Canada and that machine simply worked no matter the temps - I recall many times when it was near -40° and she sparked right up and went to work when my other cars didn't start. She made noise, for sure, but I had no qualms taking my S10 on a bitterly cold Christmas eve on a 450 kilometer round trip to pick up my sister .... and that is just one example.
That was a great little truck!
Edit: I failed to mention that it was Christmas eve of 1998.... the truck was nearly 15 years old and had about 170,000 klicks on the clock. Just never a worry.
I always liked the Iron Duke sound. Reminds me of childhood. Heard that sound everywhere in the 80s
The most iconic engine sound of the 80s.
My uncle used to have an 87 S10 with the “lo-Tech 4” and 4-speed manual (Borg-Warner T4, I believe), in lovely forest service green. It was a great little truck. Slow as molasses, but dependable. It was his daily for quite a few years, reserving his lifted 77 F150 4x4 (which he still has) for towing and other full size pickup stuff. He sold the S10 after he grenaded the rear end.
Those little 4 bangers are practically bulletproof if you replace the plastic timing gears with metal ones. They’re about as smooth and pleasant as an old Whirlpool dryer, but you can’t deny they have character.
I remember these things shaking under the hoods of many early to mid 80’s GM cars and trucks.
All the way through 1993... Now they just rock boats.
And shaking the dashboards when sitting at stop lights.
@@andyk6796 Yup that's one of the main memories I have of mine, that dash and steering wheel shaking like a polaroid picture 🤣
@@andyk6796
I worked for a used car wholesaler back in the 70’s and 80’s. I remember two occasions when ferrying GM vehicles equipped with this engine from Chicago to Milwaukee not making it home. I had two of them blow up on me. This is in the days before cell phones. Oh what fun. Especially in winter when both of them blew up and it was damn cold out!
Interesting... I must have been quite lucky, then. My 1987 Pointiac Grand Am had an Iron Duke and it ran like a top with no noise and extremely reliable for 135,000 miles. Really enjoy your videos!
I hate spamming this comment, but do you happen to know the officially prescribed method of accessing the distributor or distributorless coil packs/ignition module on the transversely mounted iron dukes? Does it involve the removal of the intake manifold?
I agree, we had a Old Cutlass Ciera with the iron duke and I never noticed the noise. It was a good engine that really held up to a bunch of teenage drivers.
I had an 89 Grand Am with the 2.5 that was indestructible. Drove it everywhere!
@@gregorymalchuk272no you don't have to remove the intake to do ignition service
@@clivevreeswijk4555 I just barely ended up doing it without removing anything. I did it virtually blind, operating only by feel. It was made worse by the fact that the two studs that the two coil nuts go on kept falling down into the ignition module, and they didn't stick up far enough to thread the nuts on. I don't know what I would do If I needed to do something more involved, like remove the ignition module/crank position sensor underneath the coils. I don't even think the late N bodies had the dogbone people are talking about. They had a transmission torque strut, but it wasn't under any tension and releasing it didn't help rock the engine forward. Now it runs, but runs rich at idle, but is drivable. I can see live data and it reverts to open loop with only a 45 "oxygen sensor rich" code. I'm still trying to figure out that one. Maybe an intermittent misfire through leaking spark plug leads? Or a failing ignition module. Whatever it is, the computer isn't picking up on anything other than it running rich.
This is the second video you've been hard on the Iron Duke. I've owned dozens, yes dozens of them without complaint. Easy to work on, parts are cheap and it's great on gas.
You are correct on all accounts!
Maybe you have an answer! Do you happen to know the officially prescribed method of accessing the distributor or distributorless coil packs/ignition module on the transversely mounted iron dukes? Does it involve the removal of the intake manifold? I lost spark on an 87 distributorless iron duke and am suspecting a bad coil pack or ignition module and have no idea how to access it. The V6s had such easily accessible coils.
@@gregorymalchuk272 Have you tried asking this question in some relevant car forum? I wouldn't be surprised if the question has already been asked and answered somewhere.
There are also Hane's manuals for your particular car, though the old ones were much better than the new.
I'll also add that these engines are great in extremely cold weather. -40 start up is no problem. I've also had dozens of cars with this engine from the 1970's thru the end of the 1980's and never ran into the phenolic gear problem. Just lucky I guess !
@@HAL-dm1eh I'll try to find a forum to post it in. It's just that most of the iron duke stuff is in the S10 and to a lesser extent the Fiero communities, but they don't have the same setup as the front engine, transversely mounted sedans. The consensus here is to unbolt the dog bone motor mount and swing the engine forward to gain access from the top. I have the Haynes manual for the N body but it doesn't give much insight. Though I haven't read it cover to cover.
I just parked my 1988 Pontiac Fiero for the winter. Still running well and I am already looking forward to the arrival of spring!
Definitely durable. I have a good friend who bought a new '87 S-10 pickup with this engine. He STILL has it today and it STILL runs. He doesn't drive it much anymore it mostly sits in the garage. Sentimental to him. But the fact that you can still start it up, head down the road and have no problems, even though it's never been rebuilt or had any major work, is a testimony to this motor's reliability.
1982 Skylark 2.5 had the thermostat on the back of the head, with a spout that had a cap like the radiator. Thermostat had a handle to assist with removal. Such a super useful design. Replacement of thermostat took mere seconds. Sure wish this was used in all cars.
Mostly this was done to assure a full coolant fill given the radiator was mounted pretty low in these cars.
And they were tough, dependable motors ever made by anyone. But Americans have developed a habit of not finishing the job(fine tuning)
You only need to replace the thermostat every 10-15 years on any decent engine.
@@fastinradfordableA lot depends on the stat too...I once had a name-brand (which I won't mention) stat fail-- in the CLOSED position, no less!-- in no time, like under 2yrs /20K miles or so.
Had one in my 85 Calais, and it was so faithful. Once bemoaned to a Russian mechanic here in Canada that I wished I had the 6 cylinder - he scoffed and said thr Iron Duke was over engineered and offered to buy my Olds on the spot.
I love the old Iron Duke! I am having flashbacks of that low-"Tech 4" EFI system.... LOL I think it was a great engine in the Fiero because it was all iron, and until you learned how to properly burp the cooling system in a Fiero, they would have bad overheating problems. Starting up the Fiero with the sunroof open was a great way to startle a passenger.... "Wait.... is the engine behind us??" (Wait until you notice the sound of the electric fuel pump in the tank between our seats.) Now if only I could have bolted a Chrysler Dive-Bomber gear reduction starter to the Iron Duke....
Pretty much any car with electronic ignition or any form of EFI is going to have electrolytic capacitors (besides just in the radio). I cannot imagine how many cars must get scrapped because of bad capacitors.
They're like little storage tanks for electricity and tend to look like little beer cans soldered to the circuit boards. Like beer cans, they go stale from age, but heat cycles (Cars are bad for this! Think of the hot car on a sunny day, then you turn on the AC... Or a cold car in a northern climate, then you start it and drive it) really accelerate the aging. My 1985 Fiero 2M4 SE was about 15 years old when its capacitors started to get flaky... and I had just rebuilt the engine myself in my driveway.
Symptom I had? No start. Good crank, great compression, good fuel delivery, good spark, but no start. One time, stranded at a gas station, I pushed it out of the way and hopped in, dropped the clutch in desperation, and the engine came right to life. And it was consistent that when I could not get it to start, I'd roll it and pop the clutch and drive off! Infuriating. And, of course, the sort of intermittent problem that a mechanic would not be able to reproduce without driving the car every day for a week. In an automatic vehicle, it would just present as an intermittent no-start.
Remember, every single day after an electrolytic capacitor is manufactured, it is gradually going bad. An EFI system with original capacitors will become more unreliable every single day. Until your Grand National won't start. Or your 2006 Toyota Corolla just throws an untraceable Check Engine light or any number of a million other problems that will happen with ALL electronically-controlled engines. Used parts will NOT help you long-term because the capacitors will be just as old in the replacement ECM as in the ECM you are replacing.
My background is in electronics, especially vintage electronics (radio and TV sets). I was sitting with meters reading the 5V rails to the TPS and MAP sensors and other stuff.... All looked good during cranking, solid 5V. WTF?
I was working on radar video systems for a major US Defense contractor. I borrowed a Digital Storage Oscilloscope from work and connected it to the ECM's 5V rail. Cranked the engine, then looked at the scope - as the engine was hitting compression, the starter was loading down the ECM's 12V supply to below 5V in super-quick downward "spikes". The 5V regulator was therefore shutting down and forcing the ECM to reset. As it was resetting, it was losing spark timing and so never got it right to fire the engine.
Took apart the ECM. Found a few capacitors with bad ESR ("Equivalent Series Resistance") caused by capacitor age - the capacitors were no longer capable of dumping their charge fast enough to smooth out normal transients caused by the starter hitting a compression stroke. Got good replacement capacitors from a reputable electronics supplier (do NOT buy capacitors off Amazon, they will be counterfeits or old!) and soldered the new ones in place of the old ones. I think the Fiero was only a double-sided board, modern stuff is going to be a multilayer board and requires really good soldering skills, but it is do-able with minimal electronics tools and a steady hand. Also watch for corrosion from the liquid electrolyte in the capacitors leaking and eating the conductive traces on the board - you can fix this carefully in most cases, but it has to be done well or the engine could stall at a Very Bad Moment like merging onto a freeway or making a left turn.
Hopped in, turned the key. The Iron Duke came right to life. Rock-solid on the 5V rail to the TPS. No more reset being asserted to the CPU chip. I kept up the habit of parking the car on hills for a while until I was confident that the problem was in fact, cured.
@shango066 does electronics repairs and resurrections and covers an ECM/ECU repair right here:
czcams.com/video/RUhvuCwVIl4/video.html
Hope this helps someone keep their old EFI car or truck running.
Mosfets wear out as well i went through all of this with my 87 Ranger. The caps were replaced and it still would drop the back two cyl. Turned out the mosfet that drove the back two injectors was failing solder joints looked great. Replaced and its still running great love how simple first gen fuel injection is. My truck has 1.3 million miles on it everything fails after that much drive time.
Thanks for the heads-up...one MORE thing to worry about now...😭
Interesting, I am more familiar with the ECU's in the tuned port F body's. Those ECU's have no electrolytics everything in them is surface mount.
I could be wrong, but I heard that GM ECUs of this era had no electrolytic capacitors. I don't know if they used tantalums or simply omitted them altogether. Most ECUs will run ok without their electrolytic caps, it's only when leaking electrolyte starts eating up traces that problems crop up.
Someone I knew had a Pontiac running a 2.5L. He was so proud that it was "a Tech4!" Yeah, that just means it has EFI. It sounded awful, but did the job. Seems the louder and rougher the Iron Duke was, the more reliable it turned out to be. At least the noise told you it -was- indeed running. Now, our 2015 Equinox has a (fairly) nice sounding 2.4 that makes 182hp. Big difference in technology.
And not to pick on you, but that 2.4L is infinitely less durable.
Keep an eye on the fluids in that 2.4. They are known to become heavy oil drinkers before hitting 100k miles. There is actually more demand than supply for replacement engines mainly due to people not checking their oil. Nothing worse than seeing people put on a waiting list while being without transportation.
2 weeks ago we had 6 of those in the lot and shop - All timing assembly jobs
that 2.4 is absolute trash. Definitely watch the fluid levels in that…it’s a thirsty engine with sketchy, at best, reliability
I've heard horrible things about the Equinox being severely under powered. Also, no shortage of them in my local U-pull-it yard. Does yours have turbo?
In my 89 S-10 2wd 5spd...that noisy bastard of a 4cyl was magnificent. I'll never forget plowing down the freeway to Grand Forks at 80mph and the lil S-10 was loaded to the gills with cargo and sounded like the Memphis Belle.
Having worked on these in the day, the primary source of noise is too much backlash between the cam and crank gears. Early on, replacement gears still had too much backlash and continued to make noise after replacement. Later a revised gear set hit the market and the engines were relatively quiet.
The Iron Duke in rear drive cars had intake and exhaust on the same side as it was based on the 250 / 292 inline 6, this configuration continued on in boat and industrial applications ( like forklifts and generators ) expanding to 3 Liters . In fact, the 3 L was available in the GM performance parts catalog as a 3 L Super Duty as some were road raced in Fieros. And. . . the company Blueprint Engines still builds a version of the Iron duke for industrial applications. There is even a prototype with a GM LS V8 head.
Front drive cars got a cross flow head and later a tubular exhaust manifold. These tube manifolds tended to crack where all of the cylinders joined together however there are easily welded with a MIG welder running regular mild steel wire. ( I had a spare cylinder head at the ready to use as a welding fixture )
The N cars used a shorter version of the " Tech 4 " as under hood width was at a premium.
Interesting post. Thanks.
The engine that was based off the 250/292 six was never called an iron duke. That was the Chevy II 4-cylinder which was actually based off the Chevy 194 six. Only the Pontiac designed engine is called the iron duke.
@@Cream_of_sum_yung_gai The Iron Duke / Tech 4 were not clean sheet designs by Pontiac, all they did is take the non cross flow headed 4 cyl and designed a cross flow head as well as making it front drive capable. ( Side mounted water pump , smaller bell housing ) The timing cover gasket ( all the way up to the N cars) is the same as a Chevy 250 / 292 inline 6 .
The last " real " Pontiac engine was the 265 / 301 V8 that went away in 1981 ish so Pontiac engine engineers didn't have much to do so I'm betting this is why the 4 cyl was attributed to Pontiac. All the other divisions still had their native engines going or were busy working on moving to corporate engines.
Calling any of the 3 four cylinder engines Iron Duke is generic enough that anyone in the biz knows what someone is talking about.
@@bobroberts2371iron duke has the distributor at the flywheel end of the block, Chevy II has it at the front. Head bolt and bore spacing is also different.
Many of the old post office trucks still on the road have the mid 80's GM S10 chassis with the 2.5 engine. After almost 40 years and several hundred thousand miles they are still running.
Was never a huge fan of the Iron Duke to drive, but can’t deny it was an absolute tank of an engine.
I absolutely will miss it when they phase out these old mail trucks. I can always hear it coming long before I see it, and half the time can tell the mail went even if I’m no where near a window lol
Will be a sad day when they park the last of these
I have one on my route. They are reliable and user friendly but are very abusive as far as handling and fumes.
we had a 91 Grand AM LE 2 door coupe with this motor. It was quiet and smooth. However, when we owned it, I was a teen age boy with my new to me license and would drive it very hard. It got noisy after a while but never broke. I think it was those timing gears that just started clattering. It had good pick up for a small car. It would easily spin the 14" pontiac alloy wheels with p205 65 size tires. Once I drove it from San Francisco to LA averaging 95 - 100 mph. I made it in 3:40 min non stop. Car took it like a champ.
The thin stamped steel rocker arms also added to the clatter on the 2.5 and the 2.0 in the Cavaliers. Adam is right that if you didn’t beat on them they could last pretty well if not gracefully
Stamped rockers are alright provided the following things are done.
1) Thick enough steel is used.
2) A proper punch and die maintenance program is set-up and followed. This makes sure you have the proper radius in the bearing area, the correct radius on the tip that rides against the valve. And a properly formed pocket for the pushrod. Plus all these things have to be on their proper relationship.
3) The rockers should be run through a heat treatment process and properly tempered.
4) The lubrication system needs to pump enough oil up through the pushrod and the rocker arm oil hole.
I worked in a facility that produced stamped rocker arms along with other stampings. We had one die maker all he did every day was take care of the punches and dies for ru ocker arms. One press, that's all it did. The most fascinating thing about their production was a small press, maybe 5 ton, that punched the oil hole in the pushrod seat. About 1/16th in diameter. Straight through steel 1/8th thick.
With a steel timing gear swapped in this could be extremely reliable. gear driven timing is the 300 inline secret to reliability.
Not a rocker arm issue. Most of the noise comes from too much backlash between the cam and crank gears. There was an updated gear set with minimal backlash that took most of the noise away.
In Michigan the unibody rusts away before the engines give up the ghost. (If used moderately)
I had a cavalier. 1997 2.2.
500,000 miles before it died.
When I was in my high school, a friend of mine had a Pontiac firebird that had the iron duke teamed to a 5 speed. It was slower than death, loud, and crude but never broke down.
LLV's most certainly are long life vehicles. They nailed the name for sure.
In the 80s I remember hearing cars drive up the street in the summer. I could always tell if it was a Tech 4 without looking.
The first Iron Duke I remember hearing was in the back of my brother's 1984 Fiero.
That would be the worst application of the Iron Duke. For some reason, GM put these in cars without a temp gauge, and when they overheated it caused a lot of fires in these cars. Also, people revved these engines higher because it was a sports car. They didn't live too long in Fieros.
That being said, I'd love to have one.
This is a very familiar sound. Their were a lot of them, back when we all used to buy North American cars.
A video on the quad-4 engine would be interesting. I remember many people were left stranded by GM with that engine.
I owned four Chevy Celebrities with this engine. It WAS NOT "great", but I was NEVER "let down" by it!
@@johnmaki3046 I think he was referring to the Quad 4. That, as I remember, had some problems. I remember the Quad OHC was also troubled.
My 1st car was an 85 Plymouth Reliant with the Silent Shaft mitsubishi 2.6. It was smooth as silk, pretty impressive for a big i4.
That's why people bought the Japanese engines.
I had an 83 LeBaron Convertible with the 2.6L "Astron" engine as it was called by Mitsubishi. Great engine, very smooth, not very powerful (92hp I believe), but you never really noticed it in that car, it pulled it along quite well. Compared to the Chrysler 2.2L engine, it was silent since the 2.2L as it aged started to sound like the iron duke engines, but they are still reliable engines.
AFAIK Mitsubishi pioneered the use of balance shafts, and back then was the only automaker using them. At some point they licensed it to Porsche for use in Porsche’s 3L 4-cylinder engine.
I remember all those Bitsumishi engines having nice sound and performance compared to the 2.2L/2.5L K-car engines, but they did get to be known for oil burning and blown head gaskets. Of course, the 2.2L K-engine will blow a cylinder-to-water-jacket hole into the head gasket pretty quickly if you overheat it. But the 2.6L Mitsubishi engines (and the Mitsu V6) didn't seem to last as long, at least around here. We go from -40C to +30C from winter to summer, so imagine Ottawa, Canada as being Detroit's climate but colder. I think the heat cycling from -40C to thermostat temp was harder on the Mitsus than the Mopars.
And made a nice rattling sound.
Boy, that is a key sound of the 1980s and it was everywhere. The weird thing is that common sound of the Iron Duke made my Calais’s Quad4 feel and sound like a finely honed Swiss watch!
The Quad 4 was a relatively smooth engine and when equipped in the right car produced exactly twice the hp of the Iron Duke. Quad 4s get a bad rep, but I had one in a 1989 Calais and it was pretty stellar. The early ones were trouble prone, but the later ones were sorted out.
@@paulwindisch1423 I loved my ‘90 Calais with the Quad4. It was seriously quick for the era. I could easily keep up with 3 series Bimmers and Saabs. My only complaint with the car was I wish it had 4th cog In transmission. Otherwise, nice light car with a people engine.
Heard the Iron Duke today outside my home as the mail was dropped off. Always reminds me of my long departed Grand Am.
For sure! Out family had a 1984 citation, manual transmission, and 1985 celebrity wagon, automatic with iron Duke power. Pretty coarse and noisy! But we were fortunate, both vehicles and engines were very reliable and we’re still going strong at 250,000 miles when we finally traded them off. Both engines were still healthy, neither needed any internal engine work at all. the cars were wearing out.
They really shit the bed on the minimal vibration part 😆
It's funny you mentioned the run-on issue. We had an Iron Duke in the first year 1985 GMC Safari. Darn thing had an annoying habit of sitting and chugging well after you had removed the key and walked away from it. It would eventually kinda rev up slightly and then finally shut down. We replaced the carburetor twice and never did eliminate the problem. Gotta love it!
Yeah, the TBI EFI Iron Dukes can't do that as fuel supply is gone. TBI injector is triggered by ignition pulses. Distributor, ECM and fuel pump are all off with the key. I guess the trucks didn't have TBI by 1985 in all markets.
Almost any carbureted engine can do this, but the Iron Duke was more prone to it than a lot of other engines. As long as the engine is still spinning, the fuel pump is still filling the float bowl in the carb, and something in the combustion chamber is taking the place of the spark. If you try hard enough, you could probably set up an Iron Duke with a carb to run (badly) until the fuel tank was empty.
This is a classic dieseling problem - check your plugs. You will likely find that your plugs are fouled with fuel (too rich) causing carbon deposits to form in the less-than-ideal combustion chambers. Get your air/fuel correct, get your ignition timing right, make sure it's coming up to thermostat temperature on every drive, and the problem will likely go away fairly quickly as you burn off the carbon deposits. Casting flaws in heads or pistons could theoretically cause this too, and they will NOT burn off.
Also, make sure your spark plugs are the right heat range, a hot ground strap can cause dieseling.
LOL.... also, check evap system, if it's full of fuel, that might cause an EFI Iron Duke to diesel, but you'd still have to have carbon deposits, casting flaws, or grossly bad heat range plugs to do this. Your Check Engine light would have been on for months for the carbon deposits to get bad enough.
Here’s how to not have it run on. Do this every hot shutdown. With engine running, put transmission in drive. With left foot on brake, right foot hovering over gas pedal. Turn key to “off” (not lock) turn steering wheel (try to) and give it gas. The slight load of the transmission, and of the power steering pump, will be enough to help it shut off instantly. No more embarrassing run on/dieseling.
Or simply use a higher octane fuel.@@BrainDamageBBQ
Dieseling was not a new problem - I recall as a little kid my parents borrowing the '67 Chevelle of a friend who acquired it from their retired father, and that basic Chevy (probably its 307 V8, maybe?) surprised all of us when it ran on after my mom shut it off. Just think, this was a '67 that predated any of the emissions attachments that were so often blamed for such issues in the '73-'74 spaghetti-covered engines with air pumps, etc., of the pre-catalytic converter era. Maybe it was the Sunoco "Economy 190" low-octane gasoline we pumped into it?
Netherlands, early eighties: at a very young age, I bought a pristine light blue '77 Monza 2+2, 2.5 aut. from an elderly woman. It had run about 40K mls.. It looked great, so I loved it. Speed limits in Holland prevented me from ever over-revving it. Nonetheless it developped a nasty cold start with rattling hydraulic valve adjusters. Otherwise it ran well and it was quite torque (in comparison to small European cars).
I vividly remember it shaking of it's radiator-hose several times. The shaking was so bad that even the radiator pipe broke a few times. My next car was a V6 Capri, then I realised what a sorry engine it really had been ...
Always liked the look of the Monza, which anticipated some of the styling of the coming decade.
@@martinliehs2513 It's styling still holds up. It looked even better than the comparable Opel Manta. Only, because of the Vega underpinnings, it was a wee bit to narrow.
@@martinliehs2513 Having owned a Monza Spyder and a 3rd gen Camaro, I agree! Even the rear suspension of the Camaro looked like the Monza's! Lots of engine choices in the Monza, depending on the year and area emission requirements, in addition to the 4 cyl, you could get a 3.2 or 3.8 Buick V6, or a 4.3, 5.0 or 5.7L V8!
@@joesmithjoesmith4284 Good luck on changing the sparkplugs on the V8's! There are still a good few V8's around in Switzerland btw.
MerCruiser also used a large number of these engines for marine applications. Various other equipment manufacturers also used this powerplant.
FYI, the composite cam gear actually quieted the engine down by quite a few decibels. This is why GM went with the composite gear in the first place. As a side note, I think the vast majority of the noise this engine produced was related to the piston skirt length and the later models having a roller valvetrain. I think GM went roller with this model in the mid 1980s. 1985ish?
I used to be able to recognize that sound from a block away.
Rude crude and ready to cruise. I love the one in my 86 Calais.
Part of it's character. Sounds like a tractor. Trimmed like a 98.
I have an 87 iron duke that lost spark on cylinder 1 and 4. Do you happen to know the official method of accessing the distributor (on yours) or the coil pack on mine? I can only figure that you have to remove the intake manifold.
Maybe not "great", but these cars had CHARM! I have owned a few, and COULD NEVER "hate" them!
@@johnmaki3046 I always took those attributes [negatives? not for me.] of the Iron Duke as part of it's character. There have been three in my family. Two I have owned personally. Would love to have anything with it, perhaps an S 10. Or an AMC Concord. That would be a scream.
Well, it ran.@@DaveGreg100
I remember it well. My grandmother’s 1987 Oldsmobile Cutlass Ciera that she bought new & owned it until the day she died in 1999. had the 2.5 Iron Duke 4-cylinder engine and 3-speed automatic transmission. It was a good car & reliable, but was definitely underpowered especially when the air conditioning was being run in the summer time. It was definitely more reliable than her 1982 Buick Skylark with a carbureted V-6 that it replaced.
Oh yeah, these engines were dogs in the A body. I drove a Pontiac 6000 back in the day with this engine. It might could top out at 80... Might...
@@keithjackson286wow! Really??
Mine was fast top speed at 190km/h German autobahn
It was a 1980 skylark with some modes on the engine.🙃
I remember the Iron Duke inline 4's being rough running and course. A person who was used to a smooth and powerful big-block Oldsmobile or Buick would often choose a Toyota Camry or Honda Accord over a GM product of the era. In its defense, the Chrysler "K" cars were equally bad or worse. Truly a sad era for the American automobile industry. The US manufacturers never regained the dominance they once enjoyed.
Lol. I've got 2 iron dukes in my collection and also a 2.2 chrysler. Both crude in different ways
The Mopar 2.2/2.5L K-car engine was clanky and noisy too, none of the gear growl of the Iron Duke because of the OHC timing belt. I like the Mopar 2.2L, after 1984 or so they really had the bugs worked out of it pretty well - just don't let it overheat or you will be needing machine work on the head. I am really glad GM didn't put something similar like the Cavalier engine into the Fiero, the all-iron Iron Duke tolerated overheating pretty well and until you learned the tricks to burping the Fiero's unusual cooling system, you'd see the temperature gauge do some pretty wild things which would have killed the Cavalier motor or the Mopar 2.2.
I dunno. I had an 84 Dodge Aries wagon. 2.2 ran like a top.
I owned two Japanese cars; an '83 Nissan Pulsar (Turbo "4") and an '83 Mazda GLC. I WOULD NEVER, EVER REPEAT THIS "experience"!
@@21Piloteer I had the same and I remember the GROW from the engine when I drove it uphill or from a stop light when fully loaded. By the way, I bought it used for a deal and it had a 4 speed manual transmission and a bench seat in the front. The stick shift was mounted on the floor and came up and over the middle of the front bench. Needless to say, no one could sit there. I only had it for about a year but it did hold up fairly well.
In the 1980s My girlfriend had the 2.5 in her Cavalier.
I spent one afternoon trying various shims to quiet the starter noise, with little Improvement. The car ran strong for almost 200,000 mi.
I’m pretty sure the Cavalier never had this motor unless someone jammed one in aftermarket? Did she have a Citation or a Celebrity perhaps?
I agree that the engine’s sound is fairly crude ..and am reminded of that daily as the mail truck comes by… but I’d submit that the 2.3 liter aluminum block engine in the early ( pre Dura-Built 140) Vega was cruder.. especially at idle.
I agree. I owned a Citation with an Iron duke 2.5 but as embarrassment goes it didn't hold a candle to the early Vega's with their farting engines.
This guy is a vast knowledge of everything Automotive blows me away every time I listen to one of them. Good job.
I personally love the sound of these engines, but then again, it's my childhood and very recognizable to me from when I was really young. We had a 1986 Oldsmobile Cutlass Ciera with one of these engines in it and it was probably the most comfortable car I ever sat in.
I liked the sound too... Lol. It was the complete opposite of a Honda engine. What the Iron Duke did have going for it, was good fuel economy. And that was a good thing in the 1980's.
I had a 80 Jeep CJ5 with an Iron Duke. That thing was unstoppable. Wish I still had it.
Suggestion for a future video: Best and worst Big 3 (or 4) CEOs. Would love to hear your thoughts.
Oh boy.
@@RareClassicCars C'mon, Adam. You can get Bob Lutz to talk shit on everyone! It'll be fun!
Or, how about best/worst major investments by automaker and era or decade?
Adam, Bob Lutzs animosity towards the goat ( iacocca) is so noticed...hey, Lutz was at GM when ship sank...js
Here's my list (since Adam won't do a video):
GM Best: Alfred Sloan
GM Worst: Roger Smith, Mary Bara (tie)
Ford Best: Donald Peterson
Ford Worst: Jacques Nasser
Chrysler Best: Lee Iaccoa
Chrysler Worst: Lynn Townsend
AMC/Rambler Best: George Romney
AMC/Rambler Worst: Roy Abernethy
Had an ‘87 S10 with a 2.5 and 4 speed. Completely indestructible. Loved that engine.
Crude but admirable. That's the best I can describe the Iron Duke. My sister had one in a 1986 Grand Am (loved that car!). It went 178k miles... 😊.
You forgot to mention that this engine replaced the Chevrolet Vega engine for not being reliable. So this Duke was a HUGE improvement there... Lol. With that being said, the QUAD 4 was another bad 4 cylinder from GM. You can't hardly find those anywhere.., so the Iron Duke isn't really that bad.
I bought a pristine 82 olds omega 2 door with the iron duke in 1995 from a little old lady, had less than 50k miles. Needless to say, she had never had an oil change done. I changed all fluids but it still spun a Rod and main bearing within a month of purchase. I had to pull it and completely rebuild it. It lasted me from 1995 to 2005 and still ran great when I gave it away. If I remember correctly the cost of internals was cheap, It used Chevy 350 pistons and rods and Rod and main bearings. The phonetic gear was never a problem for me. I had the single fuel injector fail twice(TBI). Also the engine top Mount shock absorber(from the engine bracket to the radiator core support) would wear out, and would cause extra noise from the engine bay. It was a very reliable engine once I redid it
Actually it had the same pistons and rods as the Pontiac 301 V8, designed at the same time, which had the same 4" bore and 3" stroke...the Chevy 350 had the same 4" bore but I assume a different pin location due to the longer stroke & shorter rods.
Even under warranty the timing gears would make all kinds of noises!! Some sounded like rod knocks!! The GM techs got good at poping out those cam gears in the frames without many problems!! At the time where I worked was a triple franchise. Volkswagen, Pontiac, and the beautiful Yugo!! Hahaha. We use to call them.... YuDontGo!! We were rebuilding whole Yugo engines before 15000 miles!! What a sad company!! 😊 Yugo engines got real noisey as the camshafts rounded off and the pistons cracked to pieces!! Some would run to the dealer but most were towed!! Sad Yugoslavian Fiats!!
You really gotta hand it to Zastava (Yugo) - they took a Fiat design and somehow made it worse!
The YuDontGo had me laughing for awhile! Great call.
My 2014 Malibu’s 2.5L is smooth, decently powerful, and quiet. Wild how far we’ve come.
That N/A 2.5, spanks the N/A 2.4s that were in GMC Terrains and Chevy Equinoxes of that time!
I had this in a nice silver 85 Olds Calais. I bought it at around 160K and was only able to put a few thousand more on it before the oil pressure would drop to zero on me after cruising on a highway.
After that it developed a horrible sounding knock which someone told me was piston slap (could have been rod bearing knock).
I drove it that way for a while more and yes the knock on top of the other accurately described sounds was embarrassing. My friends loved my car and it always got compliments (esp the interior), but they laughed at the engine.
I sold the car after it happened the second time to someone who was going to rebuild it and he tried to drive it home that way (no oil pressure at all) and of course, blew it up.
One thing I noticed about these engine is they were actually one of the best sounding 4 bangers I've ever heard with a nice turbo or similar muffler.
The truck version that was in the S10 and mail trucks was a heavy duty version with a better block and crank. If you wanted to hop up this engine in your GM car, it was almost mandatory to get one out of a truck and start from there, and it was best not to go over 150 hp.
Did you ever need to service the distributor on that car? What was even the official method of accessing it in the transversely mounted iron dukes? Removing the intake manifold?
@@gregorymalchuk272 Sorry I don't remember that detail.
Have a 89. Grand Am... 2.5 automatic... It was a rental car, so the maintenance was ok, before I bought it. It's been over 30 years now. It still runs great. I'm retired mechanic,so I do my own repairs,and service. Minor issues.... Grand kids, and Great Grandkids... They all love driving it.
My first car was an '89 Buick Skylark with the Iron Duke. That thing chucked a piece of its oil pump balance weights through the side of the block, then (after it was repaired creatively) proceeded to drive another 13k until it blew a head gasket in the hot Phoenix summer at 101k. Still have the car and plan to swap in a L67 S/C 3800, a much better sounding and performing power plant imo.
Repaired with JB weld?
I got a a 1986 GMC s15 bare bones base truck hand me down from my older brother. Iron duke, 4 speed manual, no power steering or brakes. I was 17 and it was a simple truck for a simple time in my life. I had so many adventures in that truck.
The iron duke was also a popular marine engine as well. I do recall the Mercury version did upgrade the Cam timing situation, probably OMC as well. Pretty bullit proof. Remember in a boat, the engine is at near peak revs simulating going up a hill floored going 80 MPH in a car, sometimes for hours at a time.
Yeah, I was often amazed how those 2.4L 4cylinder chevy engines held up in the stern drive application as well, even in the salt water. But, were they actually the iron duke engines?
There was the car version, the HD truck version in the S10 and mail trucks and then there was a race version you could order. Pretty sure it was one of the HD blocks and cranks.
The race version was aluminum and could handle multiple hundreds of horsepower with turbos or nitrous (which is no big deal these days I guess).
@@fleetwin1 yes, contracted directly through GM.
@@steveoh9838 Yeah, I realize these engines were made by chevy and bought through GM, but I don't think they were the iron duke variants... Nonetheless, they proved to be pretty rugged in a most brutal application
The most crude sounding engine we had was a 1.8 in a Buick Skyhawk. The two nicest sounding engines were a mid 80's Ford 302 V8 and a mid 90's Toyota 3.0 V6.
Mopar slant 6 always had a certain noise to it, though I think it was just the valve train. Also too, those things were on the road for so long they seemed louder because they were from a bygone era.
The Slant 6 used solid lifters until the 80's, and I would imagine that nobody ever took their Valiant in for a valve adjustment! Besides, they were so reliable, all you had to do was add oil and drive it.
18 years ago (to the day), I got a free 1991 Calais. It had 141K on the clock and was in fantastic condition. The 2.5L had low compression on #4 and burned a lot of oil. I had recently purchased a house out of town and the 34-mile round trip to work was starting to hurt the wallet as at the time I was driving a huge crew cab Ford pickup with big tires. This car, even with the smoke and misfire was a blessing. At 146K, I decided to rebuild the short block. The EGR valve had failed and allowed detonation to kill the #4 piston crown (broken rings). I had the block bored and assembled the engine with nothing more than new pistons, rings, bearings, and gaskets. It's a timing chain/roller lifter engine so I reused that stuff. About 500 miles later, one of the balance shaft housing bores decided to get loose and thankfully at the time a new unit was available. The engine was full of aluminum particles but I kept running it. Technically, I never even had to pay for the $850 "rebuild". As it was an abandoned car, and the previous owner was long gone, the $800 I found in the glove box six months after putting the "new" engine in means the car paid for itself!
I have done nothing but oil chamges at 3-4K mile intervals, one transmission fluid flush (125C), one set of front brake pads, three windshields, and four crankshaft position sensors within the 298500 miles. I guess I put new ball joints in it about 3 weeks ago because safety.....the left one was BAD. It still has the orginal transmission, water pump, wheel bearings, cylinder head, and suspension. It sounds like a small industrial indirect-injected diesel at idle and burns about a quart of oil every 1500 miles, but it's been a damn reliable car and still manages 25-26 MPG. I only drive it from November to May because the AC quit years ago and the stupid slotted plastic tape window regulators have broken a few times and no decent (read: US-made) replacements exist. I put snow tires on it and it goes anywhere I need to go until the first of May when I change the oil and park it for 6 months.
I am a diehard Ford guy and would NEVER spend money to buy a GM product. However, since this car was given to me, I have become super-impressed. It's no sports car, but it's treated me well and when the Iron Duke dies, I will try to find another.
A big part of the harshness is it's a large displacement 4 cylinder with a camshaft that turns in the opposite direction of the crank because of the gear to gear timing. I've built a couple fully. Going as far as to balance the pistons and rods weight actually helped make the last one I rebuilt sound less horrible and more like just another engine.
I think Honda would disagree with you from this period
great comment...
My all time favourite: The Ford HCS I4 Engine. Not sure if it was ever sold on the US market. Anyway, the rattling was so distinctive that you could specify the type of car just by the noise.
Terrific piece on the ole Duke. Along with at least one other video you’ve done on this engine I’ve learned a lot about it. Oh, and still like your Omega-lots of 80’s memories come flooding back when I see that car 😊
The "Iron Duke" sounded like crap, leaked oil, but was GREAT for gas mileage and overall dependability, which made it "A G.M. hit"!
The Iron Duke in my Astro van went for 335,000 miles when I sold it, running great. The new owner totaled the vehicle in 6 months, but engine was fine. Slow as a tractor trailer on the highway though.
That sound! I used to love turning on the AC on a cold 2.5 engine and watching it shake an A-car dash so hard the speedo needle would bounce.
Lol! They were rough running. But mostly reliable...and got good gas mileage at the time.
The 2.5 always starts in the coldest weather. My mom's started back like 85' negative 25 while my dads Caddy, and his friend's Honda's Toyota's and other cars wouldn't my mom would also make fun of them! That car was a 82' Citation was great to us we traded it in in 91'. We had a 88' Celebrity with 2.5 wagon that lasted till 200k miles never broke down, I turned it into a dune buggy off roaded reverse slammed , 3:28 ran it without coolant until it slowed down ! I miss it can't find them now in the northeast.
The phenolic cam gear was used on the ford 300 i6 as well,they lasted pretty well, but I tore mine apart to replace it with a cast iron gear that will outlive me. I can see why the factory chose the phenolic ones though, as it sounds much like a tractor - works for me as I am happy with the reliability.
I had a 1987 S-10 for 11 years Iron Duke. Fiber gear failed at 125,000 had it towed to BES and they bored it.030 over and it was still running when I sold it to my brother in law.
For a company whose last name is "Motors" GM has a number of notably nasty four and six cylinder engines. The Iron Duke, definitely. The original Pontiac Tempest "Half-a-389" that sounded like a rock crusher. But the the piece de resistance has to be the "odd fire" original V6 that Buick developed. The car sounded like it was "missing" (because it really was).
I had the last year oddfire in a ‘76 Sunbird for over 20 years.
Ya that 229 v6, it was completely gutless as well - the mileage wasn’t much better than you could get out of a well tuned 305 v8 with a quadrajet
I didn't think it too bad for a malaise era car. Of course all the emissions stuff had been removed from mine and I ran premium.@@kellismith4329
The 3.7 liter V6 in my '76 Buick Skyhawk idled pretty rough, but I did get 30 mpg on trips and kept it for 10 years.
I worked as a mechanic in the late '80s and saw dozens of those iron junk engines. Not the worst thing I've seen, but they were pretty bad. The biggest problem I remember was cracked heads.
They were distinctive sounding for sure, but that crashy starter sounded like they were made with warped flex plates. Couple months ago I had to get a 3 Cyl kubota diesel to move itself out of a situation with only one bolt in the starter, it didn’t even sound that bad 😄
The sound might have been partially due to a lightweight flywheel or flex plate .
For whatever reason, the sound of that Omega, which is identical to the sound my father's Citation used to make, just doesn't bother me; it's almost endearing. I've read that GM deliberately made the piston rods of the Iron Duke longer than those of the 2.3 L Vega engine, in response to complaints about that engine's secondary vibration, so you might do a comparison test with an original Vega, if you can find one. I do remember being bothered by some of GM's later 4 cylinder engines, particularly the 2.2 L engine in the Barretta, which was said to be related to the much despised 1.8 from the early J-cars. That engine made a booming that made the interior of the Barretta sound like the inside of a tuba; maybe GM's efforts to get more HP out of the same displacement led them to go with a noisier exhaust system. Some of the not-so-well balanced V6s of that era, particularly the 3.8 L engine in the 1993 Thunderbird also rubbed me the wrong way. It would be very interesting to see how a pre-1977 odd-firing Buick V6 stacks up against a modern engine, remembering that while odd-firing, that engine was also one of the only V6s that was perfectly balanced. Would it be ugly, or just strange? One engine that sounded like a metal chipper was the inline 5 they put into some of the early 2000s Chevrolet Colorado pickup trucks. There was nothing endearing about the sound of that thing, and no reason to think a 5 cylinder engine would ever sound good.
My dearly beloved neighbor had a Colorado that he inherited. Had multiple head & intake manifold gasket problems on a very low mileage pickup. After the 2nd failure he got rid of it & got an old square body pickup instead. Miss you Ray.
Its noisy, its slow, and its heavy, but its reliable to a fault. I had one in my 1988 Grand Am 5-speed, and it was great. Decent on fuel, although it leaked oil like crazy, but it never let me down. These things are almost agricultural in their design, sound, and power output. And those balance shafts, that was the only thing I ever had issues with in my Grand Am. They just let loose and lost the oil pump since its driven off of the balance shafts. Thankfully I was still able to source one from GM at the time (2005 or so) so I could replace it (which is easy) and keep going!
Do you happen to know how to access the coil packs in the transversely mounted iron duke? Do you have to remove the intake manifold?
@@gregorymalchuk272 from underneath the car. the crank sensor is behind the coil pack/igntion control module and it fails quite often. Its not too terrible, but its a pain in the rear.
@@MichaelAStanhope I was looking at it from that angle, but some steering link or sway bar and a transmission mount keep me from being able to get an arm up there. Somebody else said that the recommended thing was to unbolt the dog bone motor mount, swing the engine forward by about 4 inches, and access it from the top. I lost spark on cylinders 1 and 4 on an 87 iron duke with distributorless ignition. I was suspecting a bad coil or bad ignition module. What problems does a failing crank position sensor cause? I have heard of it causing no spark, but would it cause this? I had heard that the crank position sensor is connected to the ignition module and actually comes out with it.
@@gregorymalchuk272 yeah, you have a failed coil. There are 2 coils on there, one for Cyls 1 & 4 and one for 2 & 3. One of them has failed. I would replace both of them to be safe. You can do it from the top if you take the torque strut mount off (dogbone). Not sure what care you are working on, but in my old Grand Am i found it easiest to get access from underneath the car. If the crank sensor goes out, you will get NO spark at all, as in the car won't run at all.
@@MichaelAStanhope Do you think it's the coil or the ignition module? They use a wasted spark system, so I measured both the coil secondaries through the spark plug leads and got 28000 ohms. Perhaps 10500 ohms for each lead and 7000 ohms for the coil secondary, which is exactly what the Haynes manual says. Do the coil primaries short or go open? Were the coils common failure items? I'm more suspicious of the 36 year old power transistors in the ignition module. If it was easier to access I would be tempted to swap the coil position and see if now cylinders 2 and 3 are dead or if it stays at 1 and 4. But the difficulty makes me want to replace everything. Another thing is that the V6 engines would get corrosion and lose the ground through the bottom of the ignition module to the bracket, is that a problem on the iron duke?
Totally agree Adam!!! We had one in a 1981 AMC Spirit and a 1986 Olds Cutlass Ciera with the Iron Duke. Both ran great but couldn’t stand either of them so noisy and unrefined. The whole dashboard on the Ciera would shake violently at idle! It was so ridiculous. I’m much preferred the AMC 258 in-line 6. Yes my post office still uses them and I always know when the mail is here when I can hear the Iron Duke pulling away from the house! lol!!
I have owned a lot of tech 4 powered cars. I still have 2. My friends have always said that they sound like a sewing machine. I haven't lost any timing gear teeth on any of the 20 plus tech 4 powered cars that I have owned. Even my 230,000 mile 6000 that I still own has original gears. Unfortunately, my friend took the gears out on his mom's mint 1987 Grand Am (in 1995) He was in the process of trying to do a Rockford when they let loose.
Do you happen to know the officially prescribed method of accessing the distributor or distributorless coil packs/ignition module on the transversely mounted iron dukes? Does it involve the removal of the intake manifold?
@@gregorymalchuk272 I do recall it being really tight back there. The steering rack and transaxle are partially blocking the access from below. Access is tight from above because of the intake manifold like you said. I had to replace the pickup coil and module which required the removal of the distributor. I removed the front upper torque strut and rocked the engine forward. It was tight but manageable.
@@dueljet Yep. Some steering component or sway bar link and a transmission mount block access from below. I lost spark on cylinders 1 and 4 in an 87 iron duke and am suspecting a bad coil or ignition module, but am struggling to figure out how to access them. It's a shame, because the coil packs on the V6s were trivially easy to access.
@@dueljet LOL.... That was the ONE THING on the Fiero Iron Dukes that was relatively easy to get at, if I recall. The labor manual for the Fiero 2M4 was basically drop the entire rear cradle for anything. When you take out the dog bone and find a bottle jack which will work sideways you can get a lot done without having to do a four-wheel alignment across all 6 balljoints and all 8 tie-rod ends in that thing.
DO NOT trust the old camshaft gears. They can let go at any time. At least it's not an interference engine, so while it could strand you (usually on startup) you're not likely to have malice in the combustion palace to quote Eric from I Do Cars.
A friend who also had a Fiero 2M4 somehow managed to change the timing gears without pulling the engine - I do not know how, because the large gear is pressed onto the camshaft. You CAN remove and replace an Iron Duke from the top of a Fiero, I got it down to about 8 hours total to remove and replace it in the over 300,000km I put on that car in the years I had it.
After working on my friend's Fiero 2M6 a few times, I was really glad mine was a 2M4....
It wasn't a fast car, and it was seriously hard to work on, but it was such a fun and great little car when you got it working properly.
The iron duke was actually a very popular and very reliable engine. It was installed in FWD cars. RWD and 4x4 jeeps and many other applications. The only real design flaw was the plastic toothed timing gear. Other than that a pretty reliable rig.
Im a retired GM tech with 40 yesrs in the service bay.
GM also used a nylon camshaft gear with the timing chain in the late 70s V8s, they also stripped off after 100k miles. Luckily with the deep dished low compression pistons it wouldn't hurt anything and you could just put a good all steel timing set on for $40 and be back on the road. Dodge 2.5 4 cylinders also sounded terrible in that era, they have fuel saving short skirt pitons that developed bad piston slap in a few years. The dealer I worked at would get those cars for $400 or less at auction, spend $200 on a headgasket, 4 new pistons and rings and put em up for $2495 to $2995 sounding like a new car.
when I was young I bought a 1985 Buick Sommerset Regal that needed an engine. I swapped in a junkyard engine/trans and drove it for years. My 2 favorite things about it were the comfortable seats and how amazing it drove in snow. Also the thermostat was super easy to change as it was right under the radiator cap- no tools needed!
Fuel sipping , pocket pleasing front wheel drive Omega by Oldsmobile... we had one built for you! Omega! Oldsmobile....I remember this engine. I remember putting this engine in so many GM cars. I recall it was even offered in Firebird and Camaro at one point. What about Quad 4? It was a high tech 4 cylinder engine. The interesting that the 4 cylinders are more powerful and turbo charged too. I liked the fact you mentioned the GM Brazil engine. Thank you once again Adam.
He does great reviews. I want him to review the Quad 4. I drove one in a Grand Am in the late 80's. I took it back to the dealership 😂. That thing was rough.
@@keithjackson286 I would like to hear what he has to say about the Quad 4 too. He does have great videos. I never called this engine the "Iron Duke".. I always called it the Tech IV 4 cylinder. My uncle had a Pontiac Grand Am that had this engine. I had a friend that had a Buick Skylark that had this engine. I know two people who had a Oldsmobile Cutlass Calais with this engine. I recall seeing loaded Oldsmobile Cieras and Pontiac 6000's with this engine. You could hear anyone coming with any GM car that had this engine. The mail trucks are still in service as he says.
I had an ‘87 that went 310,000mi and knocked from one cyl.
Best to have a switch to override the 235’F when the fan comes on. That’s too hot. I just shorted out the CTS with a switch. Shut switch off and the SES light went back off.
I had a 1974 Mustang that I purchased new. 2.8L V6 engine with solid lifters, nylon timing gear. The engine was the same engine as used in Europe, from the Cologne, Germany Engine Plant. The engine sounded great and was very “healthy” when coupled with the manual 4 speed trans. Night and day difference compared to this engine.
My parents had that engine in their Pinto wagon.You could pass anything any where & still get 27mpg with an automatic! When it came to ice & snow however you would be better off & safer riding one of our thoroughbreds!
@@frederickbooth7970 Wow, had the completely opposite experience with my parents '75 Pinto wagon and that engine - loud, chattering from its first day off the Ford dealer's lot, and all that extra engine provided maybe average 18 MPG and no "pickup" as they used to say. But compared to how my dad described a guy in his car pool's Pinto Runabout with standard 4-cylinder and air conditioning on, that V6 did sound a little less strained.
@@70sleftover Our V6 Pinto wagon had no a/c so that may have helped on power & speed . We also never hauled anything but my dad & myself most of the time when commuting back & forth to work. Because of the Pinto`s VERY dangerous handling in ANY kind of frozen precip. we got rid of it after having it one year & went to a 1976 Volare` wagon instead. Much safer & most of the time we were able to get 22mpg on the Hwy with the old slant 225 straight 6. Absolutely gutless engine above 40 mph though when wanting to pass motor homes or trailers!
Like the old-school Explorer 4.0 V6, including the OHC variants, (which were likely from sometime in the late-1990s to discontinuation) which I remember, because I used to be in contact of a person who had a 2002 Ford Explorer Sport Trac and it was still soldering along with at least about 260,000 miles. But, it sounded like it was time to change the chains and guides, because it sounded like a bicycle at idle, LOL. In 2016, it seemed fine, still, despite the top console already being dead for a while (can't see temperature of outside or clock, IIRC)
Back in high school, one of my shop classmates had a blue 1986 Firebird with the Iron Duke & backed by an automatic transmission ( final year the Iron Duke was offered in the " F " body ).
I went to work. Painted it black. Put a gold " Screaming Chicken " on the hood. Put gold Trans Am flares & Trans Am smoked tailights on it. Installed a set of mid-1980s Trans Am wheels shod with B.F. Goodrich T/A raised white letter tires.
On the rear bumper, I stenciled in gold...
" Looks Fast! "
This engine is one of the main reasons why buyers fell in love with the Japanese 4 cylinder engines. They were better in every way imaginable. The 2.8 V6 was a MUCH better choice if it was an available option. I have a 2.8 with almost 225k in a 1987 Fiero that has never given me any problems at all and other than a starter and alternator has never needed a major repair. It also still gets 23mpg.
We went 233,000 miles in our 84 S10 before having to re-bore & have new pistons/ rings. 280,000 miles & still has original oil pump & crankshaft as well as rods too. Could not find a new oil pump with correct pressure so ended up using original as the pressure is correct at idle & hwy speed.
I had a girlfriend who had a Buick Century with an iron duke. It was loud and junky sounding but very reliable. I currently have a little S10 in my fleet with a 2.2 that reminds me of the iron duke. It's more modern but still has an unrefined "agricultural" tractor sound to it.
I agree, they are the most crude sounding engines that GM ever made. They were good and reliable engines though, particularly the '87-up with distributor-less ignition. They were fun to drive too, if you were a young teenager that had the pedal to the floor everywhere you went. 2.5 liters of raw horsepower, haha.
I remember trying to do a brake-burn with my father's Citation and it was like trying to dribble a dead cat. There was simply no high end whatsoever. But, if you let the transmission take it from idle, it was solidly in slow-but-bearable territory: never exciting, but never really agonizing either.
Perhaps you may have the answer I'm looking for! Do you happen to know the officially prescribed method of accessing the distributor or distributorless coil packs/ignition module on the transversely mounted iron dukes? Does it involve the removal of the intake manifold? I have lost spark on cylinders 1 and 4 and am suspecting either a bad coil or bad ignition module, but don't see how to access the coils. It's a shame, because on the V6s, the coil packs and ignition module beneath were easily accessible on the front passenger side.
As a late teenager & early 20`s I had the real life horsepower from thoroughbreds! Lots of raw power up to about 40mph! No seat belts or airbags. Had to hang on tight! Explains why I never got in trouble with high performance cars such as the police cars I later sometimes drove for the GM dealership later on when delivering them back to the station servicing.
Had a 2.5 in my '87 S 10....never left me stranded in over 100k miles. Although I was always changing the oil because the pan only held 3 quarts. Fun little truck
When I was a mechanic at a Chevrolet/ Oldsmobile dealership in the 1970s, we had the precursor to the " iron duke". It was the same engine except it had aluminum cylinders! That one made some memorable sounds as well :) The fix was to fit cast iron cylinder sleeves in those aluminum blocks, viola, the Iron Duke.
Hi Adam! Great video! I actually enjoy hearing the occasional tech 4 out in the wild ( or our LLV that delivers my mail) as it brings back a lot of great memories. I guess having grown up in the '80s/ '90s caused this. I have pointed out to you via other posts that the engine did have some advanced features like a roller cam, stainless tubular exhaust manifold, TBI, and a nifty flow-through head design. Not amazing by today's standards, but it is unfair to hold the engine to contemporary standards. I think that your calculator watch is cool, but totally weak and useless when compared to your smartphone. We can probably agree that my previous statement is an unfair and silly comparison. The same goes for the tech 4/ Iron Duke. I worked at a Buick Pontiac dealership for several years in the mid 1990s. I was a teenager at the time and had the privilege of working with a lot of seasoned and talented guys. None of them were overly critical of the engine. The old series 1 3.8 liters were rough running and a little crude too. The old 2.8 had issues too (Intake gaskets, etc).
My 2.8 came with loose intake manifold bolts but with the help of a Snap On flex socket I was able to torque them to service manual specifications and no more problem. That thing had dual valve springs!
The 2.8L was a great engine in the smaller X-cars, but when GM put in the S,T pickups/Blazer/Jimmy they won't so great. Besides the head gasket issues they would take out cranks and very hard to work on because of the space in the engine bays.. spaghetti vacuum lines, feedback carbs, marginal electronics and list goes on.
A friend used to have one of those small S 10 type trucks and got good service but it had a larger V6 that I think was based on one of the smallblock V8s. I did at a point with my Citation managed to get the headbolts to turn a bit tighter,to the factory torque specification. Also had the car rigged with a switch under the dash that when turned on made the electric radiator fan run constant. When sitting in traffic or something that would make the temperature gauge rise I would turn that switch on. I got over a 100,000. miles on it by the time I got rid of it,mostly because of floorpan rust.
By the time the S 10 and small Blazer matured with the larger V6 it seemed to have become a pretty decent vehicle but of course whenever GM got something perfected seemed to have been the time that they discontinued it. @@michaelmurphy6869
Was Car and Driver holding it to contemporary standards of the time when they cynically referenced it as the low-tech 4?
@@ButterfatFarms no, but they were not always looking at vehicles of similar price. As I have stated before, in addition to electronic fuel injection, the engines also had roller cams and stainless steel tubular exhaust manifolds. The gear drive was also better than a belt or chain in many respects (not all). They were also BMW jags like the boys at Motor Week. I believe the contemporary term is fanboys. I think it was all too easy to rip on the general whenever convenient. I have owned over a dozen tech 4 powered vehicles and none of them have had a catastrophic failure.
I remember being 18 years old and working at a car lot in 1990 and a beautiful and loaded 1988 Pontiac Grand Am with around 20K got traded in with that 2.5 Iron Duke. I asked my dad (who was an auto mechanic) to take a look at it because I was thinking about buying it. The instant my dad started the car and it ran for about 10 seconds, he said nope you aren't buying this car. He couldn't believe how loud that engine was (and the starter) and he said it sounded like it was about to come apart. I ended up buying a new 1990 Toyota Celica instead.
Ive driven a few different vehicles with that motor in my younger days i noticed that in all of them, the throttle pedal was really stiff it always took a lot of foot pressure to press it down . Was that an intentional design feature for some reason? Like to keep people from trying to rev them up too fast?
It may have been... Most issues with the Tech 4 were in the Fiero. People wanted to rev them high, and this motor wasn't made for that. Lol 😂
Yes when the x cars came out, they rigged the throttle. Pressing the gas pedal about 1/4 to 1/3 of the way down gave you 90% throttle. This was to make the car seem fast on a test drive. “Wow, I’m barely pressing the throttle and the car’s flying! Not bad for a 4 cylinder!” is what they were hoping everyone would say. It was so bad that the throttle linkage would break/snap off in a few years. Chrysler did something similar with their 70s cordobas (etc.) gas gauge would barely move from full until tank was 1/2 full, then needle would plummet fast. “Wow, I borrowed this loaner, drove it all week, and the gas gauge didn’t even budge. This car is good on gas!”
@@new2000car my experience was the opposite like the spring on the throttle linkage was super stiff
My first car which was passed through my family was an 89 Pontiac grand am with that engine. Then a 91 chevy s10. I'll never forget them. Years later I found a cutlass Calais 1990 two door! Great memories and ill never forget that sound. A loud torquey little engine!!
It was basically a tractor engine, and it sounded like it.
The Duke was based on the four cylinder that GM Brazil built. Which in turn was based on the Chevy II four.
Swap the cam gear with a cast iron one and you’re there
More like inspired by the 250 / 292 inline 6.
The name is all you need to know. The Iron Duke was a bullet proof engine! I guess if you had a lot of money you could buy a car with a quieter engine. But for the price it had no problem with the noise. Ran mine for 200k and was still running!
Any engine that refuses to stop running seemingly FOREVER sounds good to me. Wasn't made for racing, low power was a key factor in its durability. Gear driven cam was another. In front wheel drive it was nearly impossible to remove the oil filter on a neglected one in a FWD, but the Iron Duke would still always get you there. What's embarrassing about that?
Growing up my mom drove a pea green 86 Century Custom with the iron Duke. I get a flashback every time I hear my mail get delivered lol.
About a year after I got to my first duty station (1983, Wright-Patterson AFB) the local car dealers got together and were allowed to come on base to show off their new cars. At the time I was interested in a new car and the dealer really talked up this nice metallic gray Camaro. We took it for a test drive and he said "floor it!"--I assumed it was a 2.8 V6 because it sounded throaty, the engine was giving all it had but we didn't seem to be going any faster. Popped the hood after the drive and there sat the "pride" of GM...the Iron Puke 4-banger, walked away even as the dealer was talking economy and "power."
I couldn't agree more! My first brand new car was a '86 Olds Calais with the tech 4. I wanted the 3.0 V6 but in hindsight maybe I dodged a bullet. Outside of how horrible it sounded the vibration was terrible. The spokes on the steering wheel in that era of Olds were low. The top of the wheel vibrated so horribly! It was irritating! Under warranty the head gasket blew due to over torqued head bolts. It leaked from the thermostat housing. The repair at the dealership was to goop it up with silicone. I eventually replaced the housing. Problem solved! I traded up for a '91 Quad 442. When was the last time you've seen one! The quad 4 was stellar! Wish I kept that one!
Did you ever need to access the distributor in your Olds? What was the official method in the transversely mounted Iron Dukes?
@@gregorymalchuk272 it was on the firewall side of the block. I never had to deal with it. I recall looking at it and thinking about how tough it would be to get to.
Noise and resonance from tubular exhaust that would glow red hot under load, the vi ration would snap the starter outside too, replaced a few cam gears on these in the Fiero by dropping engine down at an angle to slide the camshaft out! Easy to work on.
Remember it? Millions of people all across America hear it every day in the Grumman LLV aka the USPS Mail Truck! 30 years running and still being beat on between every mail box.