A Jeep With A Misfire And It's Not The Coils, Plugs Or Injector - No Parts Required
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- čas přidán 2. 10. 2023
- In this video we have a look at a 2006 Jeep Grand Cherokee with the big 4.7 that came in with a customer complaint of an engine light and an obvious misfire at idle. This one was not your run of the mill bad coil pack or injector.
-Enjoy!
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Never ceased to be amazed at Eric's knowledge! There's a reason his garage is the last stop for vehicle repairs - they get fixed!
His garage should be the only place to repair local vehicles!
@@dennishayes65😅 If they do, Mss O would be wearing gloves with that dress. She is much needed for keeping Eric sane😂
@@RaveDaver
Next to every damn good mechanic is a damn good woman.
Would love to know what causes the problem
He should rename the shop "The last stop garage"
Eric just proves that nothing is better than a deep understanding and knowledge of how things are supposed to work.
That was brilliant, Eric. If you ever get tired of turning wrenches, please teach the next generation of mechanics. You have so much skill, knowledge, and experience and a great way of teaching.
He’s teaching with every video he produces.
@@elgastsos210He can do what ScannerDanner does. Teach in a classroom and just record it
he's already doing that
Believe me, he already is!
@@chainarmor448 His first student didn't last long. Couple of diagnostics and he was gone.
Wait, what did he just say about companion cylinders, top dead center, and little buddies? Sometimes I think we forget just how good this guy is at nut and bolt mechanics. We love what you do Eric. Thank you.
Eric always makes it look easy. Watching him do his work like child’s play has always been such a pleasure. Thank you for bringing us along.
He's got an awesome diagnostic/analyzing brain... many great mechanics that would be jealous of this gift.
Question my grand prix 3.8 v6 series 3 the car runs fine until gets warm then gets a surge of gas and nails it then bam the engine light starts blinking until i let off the gas!! Any any information please??
it's also amazing that it fell out and apparently did no damage to anything in the process.
I'm still wondering what caused it to pop out. It will probably happen again.
It could be that the lifter has failed? I’ve seen that happen where the rocker arm falls out of place because of the lifter. But then again, it would be quite loud when he started it
Eric you always do nice work, I wonder if Jeep has a bulletin on that problem ???? With a reason why it happened?
@@erictroshin3490Thats an OHC engine, no lifters just rockers
@@Erez84Hydraulic lash adjusters.
Not sure what amazes me more, Eric O abilities or the lack of diagnosis skills at the other shops
Eric you're a living legend. The concept of cylinder buddies, oh man, only someone with loooong flying hours can connect the dots out of such pico graph result. kudos.
Absolutely fantastic bit of diagnostics. Just goes to show what a real pro can do.
Waste of time lol. All was needed is a quick look in the cylinder.
@@righteous1one Oh Captain hindsight 🤡 showed up. I’d say approaching this with just the engine codes as your guide his way was incredibly quick and efficient.
@@righteous1one When's your video coming out?
@@Lq32332
Thanks for your Comment. It was on the minds of many!
Proverbs Chapter 18, Verse 2 comes to mind…
RL
@@Lq32332 Why are ya so bent about it though?
Ability to diagnose is what really sets the mechanic from the diyer so far apart. I am amazed at your ability to diagnose! Love your videos.
It separates the few great mechanics from the rest of the mechanics. Most mechanics can’t diagnose anywhere close to his skill level.
It separates good mechanics from great mechanics... for example, Ray is a very good mechanic and would absolutely trust my car with him, but Eric is absolutely a couple of steps above Ray when it comes to in depth diagnostics. Ray usually also gets there, but with a lot more poking and guessing... Eric follows the clues, the evidence and the facts and zeros in to the problem.
Well…I can diagnose but I can’t fix 😂
Swapping parts is easy, it's knowing which parts to swap that sets a real mechanic apart from the techs.
I would not called a "Mechanic" but a Technician.
Eric O, I still like the small change in your sign off: "Remember Folks, if I can do it, you can do it, and if we can't do it, we'll get Mrs. O to do it." 😊
Who'd of thunk you could find a valve problem by checking starter current, but that's why you're the best.
The original thumping noise in the beginning was a pretty good tell because that's the would-be exhaust being exhausted through the intake as the intake valve opens.
You’ve seen it before. Errr heard it before. Nice addition
If it was a waste spark you would have gotten a two stroke out of the cylinder.
“Just remember if I can do it you can do it”. You have got to be kidding me. If that were the case the vehicle would not have been to multiple shops and still not fixed. Your diagnosing skills are second to none. I just wish there was someone like you near me. 👍
Pico delivers. Waiting on the mail is the hardest part....... 😊 I didn't trust ali express 99 cent attenuators. But when my $11 ones came in they are marked 'Made in China'.
Knowing China outlaws patent infringement of their stuff, they should be safe. Gotta order some christmas tree loom holders from them anyways,
That's insanity, rocker falls off and you can just put it back on lol these Chryslers never cease to amaze me😬
Great video! Excellent diagnostic process that led to a quick result. I'm a big 4.7 guy and have done a lot of work on these engines. Overall very robust and reliable. 300k+ miles is a common sight for these if maintained.
That was a pretty unusual case for that engine to spit a rocker arm with how clean the engine looked inside. I think that it likely was because the lifter is starting to collapse; I would have pulled the lifter out and tried to squeeze it to check for any play.
Also, I noticed that the serpentine belt is routed wrong on that 4.7. I don't know why, but I see so many of these engines (3.7s too) with the belt routed that same way...even when the belt routing diagram is posted right there on the fan shroud! It spins the water pump backwards and makes the engines run hot, leading to the valve seat dropping issue in some cases. That customer probably already picked up and left but you might wanna give them a call...🙂
Thanks for the video.
Very interesting reading & observation.......
Oh yeah you're right, the belt IS routed wrong. Customer might be coming back with the same problem again soon
do you think the "thunk" noise with cranking.was from a bearing on the crank that was about to go with the stress?
No. What thunk noise? Are you being serious or making a joke that I'm not getting?? 😀 Unless severely abused (i.e., oil or coolant problems), a 4.7 generally doesn't throw bearings. If it is neglected, it will spit rocker arms or blow head gaskets long before a main bearing gives out.
@@southwestvajeeper5106 Not a joke. if you listen to the video while he is doing the WOT crank test, i think before the plug comes out, there is definitely a rhythmic thunking noise while he is cranking......he commented that he didn't expect to hear that noise but then eric never addressed what it was? the noise did not happen once the plug was removed... maybe the noise was the cylinder decompressing through its intake valve?
Sorry, I don't know anything about these motors; your comments just indicated you were really on top of them so i was hoping you could explain the noise in the video since eric O noted it but did not explain it. Thank you for your reply. take care..
The fix was very well done, but WHAT ABOUT THE LOW PRESSURE IN THE LEFT REAR TIRE! 🚙😱😁
patch kit would mean parts required.
Early morning video with coffee! Can’t beat it! 😊
As a Chrysler tech, the 3.7 and 4.7 are so common for the valve seats sliding out of the head and causing at best case spitting the rocker out. Worst case the seat gets out of position and then breaks (carnage ensues). Most common reason for the seats coming out is at some point it had got hot when the water pump failed.
5.7 does it too, along with eating cam shafts.
I had a 3.7 that spat the follower. I removed the head and the valve had the loose seat in its teeth. Several other seats were loose. I had all seats staked.
My ram with the 3.7 and ram with hemi had the same issues. I bought them cheap after the owners gave up (different owners and 2 years apart). Great knowledge to know. Other jeep quirks I learned over the years are the broken wire in the door hinges (1996-2005) that cause random electrical issues and on the newer jeeps (2006 +) the computerized shifter may be dirty with carbon but show all the signs of a bad trans. I learned so much by being a hands on home mechanic with a background in small engines (atv, zero turns, small tractors)
@@allenrussell6135 Broken wires to the door are very common on ZJs, earlier than 1996 also.
I came here to comment exactly this
That customer is so blessed that didn’t destroy that cam shaft 🤞🙏they must have some good luck lol !!!
I have actually seen this 3 times and it was always cylinder 4 exhaust follower
Sounds like its got a cam! I absolutely love the (stethoscope) relative compression test. Hydro lock was my first guess but your companion lesson took it to the next level. Your ability to zero in on the problem brings a lift when facing an exhausting work day!
I've had a few pop out on the 3.7 over the years, the root issue is the lash adjuster isn't staying pumped up. Best to replace that while the valve cover is off because odds are it'll throw the rocker again later when it fails. The little seal or valve inside the lash adjuster fails, intermittently at first. You can pull it and re-prime it with oil and it'll hold most of the time but keep compressing it and it'll just collapse at random. Eventually it'll start doing it pretty regularly. I keep a collapsed one in my box to show customers with ticking hydraulic lifters/lash adjusters and explain why changing their oil regularly helps prevent that from happening. That engine looks pretty clean so likely just a failed part. It's common enough on these engines they they make solid lash adjuster replacements where you set the lash manually like on a Honda and basically that's that until you need to adjust it again in 60,000 miles.
One in a million shot, doc...
Probably just a very specific harmonic and/or metallurgic weirdness that allows it to pop out after several trillion cycles of working perfectly.
I marvel at the fact that people transport their problem cars for hundreds of miles to you (and Ivan) for repairs that require no parts.
You provide shining examples of proper diagnosis and customer care.
The answer was in what had happened before, a new coil and spark plug which had done nothing because everyone else had not bothered to go beyond they why is the cylinder not working correctly other than making the Jeep a parts cannon.
Anyone can throw parts at a car at random or based on fault codes, but having the knowledge needed to figure out what parts it really needs (if any) is what seems to be rare!
I try to teach people don't just change plugs , pull a compression check first , no sense of putting lip stick on a dead pig ? But everywhere I go, they all got lip stick all over their shops ???
@@MikeSmith-nu9wt Even for people at home, I don't have a compression gauge, I'm not going to get one because I don't need it often enough, you can just play swap the parts on multi cylinder engines, and see if the problem follows. Single cylinder, I have just played swap parts with other used stuff to avoid buying anything until I know. Its just another diagnostic method for people without all of the tools.
i used to maintained some of the 4.7s in a fleet and this happened a bunch times, it will most likely happen again.
Yep collapsed hydraulic lifters are known on these
I'm 20 years in and haven't seen that before. That's the fun part. You just never know what's rolling in
Can't remember if it was a 3.7 or 4.7 but I had a timing chain job once. That wasn't fun. After doing research on those motors I couldn't believe Chrysler went with them. But it was what it was. It got fixed and shipped out. And the other guys in the shop got some good laughs with all of the hollaring, swearing and whatnot coming from my bay. That thing was so finicky and the parts were expensive (had to replace chain guides as well). Your customer learned a valuable lesson. Instead of being the last shop yours should be the first shop to bring a sick vehicle to. Solid diag. and easy fix. Your customer was very lucky. That loose follower could of caused lots of damage.
Sounds like Jeep hated mechanics. Took me 2 days to replace an alternator on a 2006 3.0CRD. One of the other mechanics said he'd never heard so much swearing. Why 2 days, because I got so p'd off I had too walk away many times plus had other jobs.
Someone has been revving that engine to the moon.
Mrs O ,makes the show!
I wish I lived closer to your shop! Good mechanics like you are hard to come by.
Forget the fallen rocker arm, we know it was the laying on of hands at 24:09 that really fixed the engine.
SMA to the rescue! You are the car guy! Why would you be the last stop,......folks should save themselves time, money and grief and just start with SMA!..
Fantastic diagnosis and repair. No parts used and it’s fixed, baby.
Knowing principles of operation always wins over the parts cannon. Eric proves this daily.
That relative compression test was mind blowing. So essentially, you want to go from Medieval Manuscript Calligraphy Waveform to a Dewalt Reciprocating Wood Saw Blade Profile Trace (not to get all technical here) :P
Eric is the difference between a True Master of his Profession and "parts changers"!
Our institutions are no longer teaching problem solving skills and deductive reasoning. Technology can be a useful tool WHEN used correctly. But it is NOT a substitute for common sense, logic, reasoning and experience.
It will be a sorry, sorry day when the Eric O's are no longer performing their crafts!
HEY! Good morning Eric and Mrs O! I hope that everybody has an awesome day!
I still can't understand why people don't come to you first of all, the amount of money they would save. You always have a thorough diagnosis of any problems. The amount of times I've heard you say that you were the customers last choice at fixing a car. Keep up the great work. Love from England ❤
The only thing I can think of is that his rates must be higher than anyone else, or like myself is in an area with lots of farmer shade tree mechanics.
Probably is booked out for months.
People trying to save money is why. They don't think about the whole situation, they just think of how much more money one shop will charge VS another for labor. So they go to the shop with the cheapest labor rate. Then when that shop screws up they go to the next, and so on, until they finally end up at the shop they should have started with in the first place that charges more for labor, but they would have saved money if they would have just gone there to begin with LOL.
I had a Ford Fairmont when I was a teenager. It had a 2.3. It would throw followers regularly. I would pull over and get out my 7/16 socket and pull the valve cover and pop it back on, on the side of the road. It had a bad rear main seal too. I would leak so much oil that it would catch the cat on fire. I went though a lot of fire extinguishers with that car.
Oh man does that bring back memories!!! Had one myself. Leaked oil like the Exxon Valdez!!! Pop a follower or three back in and add another 3 quarts of oil!!!
"I always start with relative compression first". That applies even without the fancy tools. You just have to listen while cranking with the pedal to the floor, it's clearly not as simple as a coil or plug. So, for those general mechanics who throw parts, don't think that the use of fancy tools is what separates the smart guys from the rest. Just by listening, right out the gate he knew it had to be some kind of mechanical or timing problem. Is current mapping better than just listening? This case highlights that it is! Brilliant diagnostics, Eric.
It may not always be a mechanical issue if the cylinder has no compression from being washed out. There are also instances a RC test can lead you down the wrong road. It's better to have a pressure transducer in the exhaust and intake when doing an RC test so you see the full picture.
Eric knows his stuff, most auto repair places do only mechanical repairs, but he does both electrical and mechanical repairs, i guess these days you have to be man of all trades in the auto repair industry other than panel and paint?🚗🚗🚓🚓👌👌✌✌😀😀
That's incredible! It shows how much common sense and knowledge of engine theory you need to brush up on to make an accurate diagnosis.
Hello there Eric, If you set a trigger on your channel with the current clamp you can force the scope to wait until certain condition are met before drawing on the screen.
We recommend the settings below to our clients.
500ms/div time base
1-2MS/s sample rate
Trigger mode of single or repeat (Single will get you one page. Repeat will get you multiple pages but the trigger conditions have to be met again)
Simple trigger
Source is wherever your current clamp is connected (ABCD)
5% Pre trigger puts the trigger point near the left side of the screen. This gives you 95%of the screen to capture your data to.
Threshold of 200 amps in the rising direction
With these settings the scope will wait until there is 200 amps of current flow through your clamp before drawing on the screen. If you have any questions or would like to discuss it further hit us up.
Right on! When I am doing an RC test I typically have the trigger at 50 amp, 10% pre trigger, 500ms/div, and a single capture. If I am being lazy (like this video) I just wait for the screen to refresh then hit the key 🤷🏼♂. Thanks for the suggestion and comment👍🏼
@@SouthMainAuto Thank you for doing what you do. If there is anything we can help with let us know.
As a clueless old guy, I had no idea that the Pico system existed. Of course no matter how amazing the diagnostic equipment is, it still requires a skilled tech to do a proper diagnosis. Excellent work! I'm baffled though that the cam follower/rocker can simply fall out and then be popped back in without damaging anything. Please let us know if it comes back out.
My son worked for Pico briefly as an intern in college... he was collecting data both good and bad for their database that they make available to those who purchase their equipment
I am surprised too about this cam follower/rocker, but, it's not a Toyota after all.
Guessing high RPM's or loss of oil pressure spit it out.
I know Dave over at the Motor City Mechanic has talked about this before. He has his own shop now, but he was a master tech at a mopar dealership. Down in Georgia I believe.
It's grandchild of oscilloscope
That engine bay is CLEAN for upstate NY!
Impressed the heck out of me. Cylinder 7 showed an anomaly but you immediately knew a different cylinder was the problem and actually what the internal problem was. Impressive. I never could understand how a relative compression test could be done electrically but your explanation made it really simple to understand. Thanks.
Don't forget he knew the problem was 4 because 4 was missfiring.
@23:02 The moment you and Mrs. O. know this is likely coming back. I have the 2005 version of this vehicle. Those hydraulic rocker lifters get clogged with sediment from the oil and then do not function correctly. It is probably the main reason the engine calls for oil changes every three (3) months or 3,000 miles - which owners do not do. Replacing only one hydraulic lifter is kicking the can down the road. The other thing I learned is that the gasket channel in the valve cover deforms near cylinders 7 and 8 after about 15 years. You could put sealant in the valve cover gasket channel or replace the valve covers. I have been doing OEM replacements for all my parts because I found the parts made in China only last 3 years whereas OEM lasts 3 times longer.
CSI South Main (Car Service Investigations). So fun to watch it get solved.
You are a very smart man. I always laugh when you say, "Remember, if I can do it, You can do it." ... ummm nope.
Hydraulic lash adjuster got gummed up and stuck down, seems like a pretty common problem on these. Replacing all 16 adjusters would be wise.
Yep been there too.
Just did this recently based on your older video. The lash adjuster had mostly collapsed though. But $20 for a new adjuster and he was on his way! Never would have tackled this without your encouragement.
Just another Eric O Master Class.
That diag was magic. I’ve never seen a relative compression test before. Way cool!
When you said a 4.7 I figured it would be the dreaded dropped valve syndrome i have seen on a couple of my 4.7. Pretty common in high mileage 4.7. New Head runs about $2k last time I had it done.
Man i would love to work with a guy like you. I have a hard time trusting any mechanic but you are amazing. Very thorough diagnostics on everything you do ruling out any other possibilities. Im a 100% honest type of person myself! Dont stop doing what youre doing brother.
I have owned several Jeeps in the last 45 years, some were old school V-8, but most of them were the 4.0 liter. Then i owned a 2006 Jeep, 3.7 liter v-6. It blew up idling in the parking lot at work, on a very cold day. Since then, we drive Toyota's !
Granted you are reaching many mechanics with your willingness to share your knowledge.
Men like you are needed to train young minds.
Many people can teach the parts of a vehicle.
Very few have the ability to describe how those parts interact with the others.
If you aren't presently an instructor, the industry needs you.
the other interesting thing is the current draw for that cylinder gets progressively larger, until it "resets". there's also a distinctive chuffing sound coming from the engine every couple of rotations.
I assume that's the sound of all that pressure in that cylinder rushing back out the intake tube when the intake valve opens.
@@jtjones4727 That would be my guess as well
I had the same thing happen to me on a dodge Dakota. I fought that for a long time then took the valve cover off and found the rocker arm off of one cylinder. Reinstalled and that solved it. Then it happened again. Tore down both sides and used Schaefer’s penetrating lube on every valve on both sides and everything that moved. Checked the torque on every rocker arm and never had another problem.
I assume at that point you also stopped cold rage starting it
I was yelling broken valve spring. Nice job teaching with the Pico.
Well, done, Mr. O! I really enjoy watching you track down difficult issues and the way that you explain what you’re doing and your sense of humor! From a long time watcher.
Thank you, Mr. O for choosing this method of diagnosis and bringing us along. That was just fascinating. This old dog learned something new about companion cylinders and how a quick relative compression test can show an engine's overall health. I must admit, that was fun, even as a spectator. 😊 Thanks again.
Mr O is a credit to his profession. Once again, well done sir and thanks for taking us along for the rie
I was going to comment on how BRILLIANT Eric is, but I’d just be rehashing every comment on this video. Eric, you’re truly a genius!! Huge respect!
Loved the comment about the 'Mustard dress' but the classicwas the comment about the police car, '5-0'.. People now days would not understand that! Loved It!
Brilliant Eric!! From 3:45 to 4:45, check the basics first, & start simple! Learned that many years ago. Retired marine tech here. I always started a repair this way. What you did to diagnose was the way I was taught from the beginning, start with the basics! Spark, fuel, compression etc. If this would of been a marine engine from where I retired from and one of the young bucks got it, they would of connected the computer up, replaced parts, then scratched there head why it still misses. Love your work & videos, keep it up!!
Very clean high mileage motor on the inside. Kind of shocked at the amount miles on it. Very well maintained.
i know that "i do cars" guys would be happy to see the motor that clean. amazing what proper oil changes do! id suspect mine 3.7L V6 dodge would look the same as this one at 205K as I change every 3K
Unbelievably intuitive, just like a detective. Gonna have to call you Sherlock.
I believe if I could hook the Pico to my brain it would have shown the primordial electrical stirrings of solving the problem with this Jeepney. That is to say compression blockage causing the current spike of the starter. I’m 68 a couple more years of O’tutelage and I’ll be a capable troubleshooter. Thanks to the O’s for another great video.
Another superb diagnosis. The question is: why did it pop out? Temporarily stuck valve? Temporarily stuck lifter? Interrupted supply of oil to the lifter? I would not be surprised if this problem reoccurs. If it does, what would your plan of action be?
it's a Chrysler
Common hydraulic lifters, they like to stick compressed until oil pressure gets to it and forces it back out
I've run into this before. Like Eric, I was the last stop on a 4.7 on it's way to the scrap yard. I ordered new lash adjusters and rockers for the whole engine after the second rocker came off. Still serving that Dakota even now. I gained a dedicated customer there. I had to use more mundane equipment but came to the same conclusion. Great job Eric, keep up the good work!
Before I even saw a second of the video, the description title triggered my memory. Way back when, I was told about a Chevy 305 long block in an alley to go by and pick up if I wanted. Well, free engine, why not? Went back there and gathered up the blue baby. The cylinders were spotless and the heads had been pulled off ostensibly for their use as a higher compression alternative. Well I had my suspicion about the real reason the engine had been replaced, and I was right. The lifters were still in the block, so I sprayed them with WD-40 and rotated the crank. Just took a couple turns to see what was wrong. The lifters barely moved for #5. Cam lobes were flattened. Here's where the engine became useful. A friend had a work truck that had been swapped from diesel to gasoline and his engine was puked. We got a Crane Fireball cam and lifters for the little engine and I had a couple heads we could slap on it. The heads were from a 4 inch bore engine. We knew they'd be low on the compression, but we also found out that the 305 head gaskets don't work under the bigger combustion chambers. They blew out right away. 350 head gaskets sealed up fine. An Edelbrock intake with a Quadrajet fed the fuel. Well, that little low compression motor pushed that C20 work truck around with authority for a long time. Best "free" engine ever.
You have the sweetest office lady/Wife cooks lunch/holds parts etc happy wife happy life
I can always say to a question: as what have you learned today? easy, I watched South Main Auto today!
Settling in for another great video Eric. Greetings from Australia :-)
Great thought process, Eric! Spot on diagnostic and repair was very rewarding - no parts required :-)
I build motors for a living and i've seen this a few times, the followers are just held by being stuck in between the lash adjusted (what you called a lifter) and the valve, there isn't really anything "positive" holding them just a sort of valley for the valve stem and the rounded seat for the adjuster. So a loss in pressure of the lash adjuster cos it's oil driven can cause have the follower fall off. A loss of pressure can be a bunch of reasons and it could be a quick momentary thing never to return, or could be a chronic bad adjuster.
USUALLY this doesn't happen even if you have a bad adjuster because a bad adjuster rears it's head when the cam pushes down and that friction keeps the follower from falling off. But if the stars align it can happen and i've heard it happen once in person on a freshly rebuilt engine, because the engine sat in the shop for a couple months and one of the adjusters didn't have enough oil pressure on first start (wasn't primed) and it popped off once developed a misfire. and everyone's face went pale. Thankfully i've seen this before told them what happened and it was a quick enough fix.
I've seen it on the ford modular engines as well, like the 4.6, 5.4s., it can happen to any V engine with the same valve design. It's not common on straight engines because gravity keeps the following from ending up sliding down even with a bad adjuster, the v engines the follower is at an angle. so gravity helps it fall off.
BTW these 3.7 and 4.7s are exactly the same design, the 3.7 is just a 4.7 missing 2 cylinders and with a longer stroke for compression. I've considered making a stroker with 3.7 rods in a 4.7 but nobody likes these engines lol.
My 05 Ram 4.7 was getting a misfire cylinder 8 after a rain or car wash. For whatever reason water/moisture was pooling up around # spark plug well and inside the boot. Was going bananas trying to figure it out. Glad to have found the problem via help from You Tube!
Great video Eric, I'm always learning 👍
Nice video. I would love to have one of those scopes, but as a DIY not often a reason for it. I don't know why Eric is the last stop except that he actually fixes the problem. His rates are reasonable and he does not seem to fix with a parts canon.
Avoca is a very small town in the middle of nowhere. Most customers have to come a long distance to get there.
Man you're one hell of a detective
Bought a 1978 Ford LTD years ago with a 351M that had been in 2 different local shops with no success at a repair. Pulled the right side valve cover to find that somehow a rocker arm had popped off 1 cylinder. Put it back on and drove that car for years and never had another problem. Best $500.00 I ever spent!!!
I am so impressed by that whole technique of compression testing. Great to learn from such a pro.
Not just a Mechanic, but a Magician!
You never fail to amaze me! Great job! Wish that fancy scanner wasn't so expensive. Of course, knowing how to use it is the biggest part of it! Rock on Eric!
Swaptronics not bad. I've always called it Swapnosis. 👍🏻
100% Mr South Main Auto!
Even a 61 yr old engineer on a 12 step program motorhead recovery program can learn on your 'tubes.
Throw the compression gauge away! Get a probe for spark input and a bnc adapter for the fluke dc current probe to plug into the Rigol scope.
Keep on mister. Upstate NY doesnt rock, but the finger lakes are beautiful. (Lived in Horseheads for a few years).
Subscribed, and thank you.
it is so fun to play mechanic with you.
I´ve been watching you long enough to think about 4 being full of air, being compressed instead going away into the exhaust pipe.
You would make for a Wonderful teacher to a bunch of apprentices.
[You would make for a Wonderful teacher to a bunch of apprentices.]. Me thinks this is exactly what is going on here 🙂
@@chiefgecko yea, might be, at least as far as the medium allows. I hope it is enough!p
I have never seen that test. So interesting and logical results. But as usual it’s the operator who makes the difference. Dang you’re good!
South main Auto when you want it fixed Right the first time!
Ahh yes. I knew what was up. My son had a Nitro with the 4.7 and I could tell the problem right away as you could hear the puff through the intake. The rocker arm popped off and we assumed the lifter collapsed as it would not click back in place. But it turned out the valve was bent. The idea of a floating rocker arm is just dumb.
Never seen that method used for compression testing, thanks for sharing and great diagnostic work!
Always enjoy your videos, even got me believing if you can do it I can do it .😁👍
Sherlock nailed it again. Simply a process of alemination, my dear Watson.
"Let's pull out the old-fashioned laptop". That's our guy, Eric O. 😎
I have seen this on various vehicles over the decades. The first time was on an old Chrysler 2.2 engine. And the solution was to simply put the follower back in and its always fine. As to why, I do not know. I have no idea. But my theory is that the valve floated or the lash adjuster lost its prime.
The same happened to me on an old Chrysler 2.5T.
On these, they are hydraulic lifters, springs tend to fail on them and they stay collapsed till oil pressure pushes them back up.
New tech over complicates things..breaks easy ..more power that's it...
@@Sicktrickintuner that may be right, but when 50,000 miles go by afterwards and the follower hasn't fallen off again....???
Eric really is "THE MAN" !
Eric, As a retired electrical engineer, I'm so impressed with your diagnosis using an "o-scope". I never would have thought a cam follower would be a snap-in component. Upon seeing the separated follower, I immediately wondered whether someone had been exploring the V-8's redline. Perhaps a new teenage driver? I know I did in my mom's '68 Cutlass oh so long ago..
A little knowledge is fine....but a lot of knowledge with intuition based upon experience is "Priceless"...!
Wonderful, I'm a factory mechanic and I try not to be a parts changer, nice to see troubleshoot the way you do it
lash adjuster/ "lifter" failed..I had a similar issue on a 3.7 and they're known for (as the dealer said when I ordered them) intermittent failure! lol good catch sir! something to do with the oil passage being too small and something floating around in the oil temporarily clogging the hole causing it to not pump up fast enough after a cycle and allowing the cam follower to leave the chat.. you know, Chrysler things!
I was thinking the same thing.