Well done. I took my 2000 Honda S2000 to the same mechanic for six years and he laughed at me when I asked him when he last adjusted the valve clearances. He stopped laughing and apologised when I showed him the manual. The car ran a lot better after that service. If you are a professional mechanic why would you assume things when there is so much information readily available on the internet? Like you say, it can save the customer a lot of time and money if you just spend a little effort learning the car, at least pull up a service sheet!
@andyoverall1951 yes a mother mechanic that doesn't realize the importance of reading the service manual the former mechanic has atheist be introduced to the idea that maybe he should if read service manual
In the 70's, a valve adjustment was always included with a major tune up in my shop. Of course the engines were 4 cylinders and easy to get the covers off. A minor tune up would have been plugs, points and condenser (what are those?), carb throat and linkage cleaning, pcv system maintenance and an air filter. Finally, timing, idle speed and fuel mixture adjustment. Of course I had an oscilloscope and used it for every tune up major and minor. A minor tune was recommended at 10k intervals and major at 50k. Timing belts at 70k and chains at 100k. Saw too many chains sawing their way through timing covers.
The best ones were Pontiacs around 1969 or 1970 . The Pop Corn Machines . On the V8's , the cam lobes , I believe exhaust , were defective and rounded down . When the intake opened , it blew back out of the carburetor . My friend's popped for a few weeks . Then when it wouldn't start , we opened the hood . The carburetor wes blown off the manifold and hanging by the steel fuel line ! I put in a new cam , lifters , STEEL timing gears and chain .
It's easy to see why valve lash adjustment is part of the routine maintenance schedule. Getting the diagnosis is not easy, especially in mild cases! Many shops won't have the time or tools to measure in-cylinder pressure readings. Also with VVT involved, those waveforms may change depending on rpm, ambient temp, engine temp, etc. Good for you to make the diagnosis accurately. For all else, respect and follow the maintenance schedule. This has to be added to my list of 'sleeper diagnoses' that don't show up on a scan tool (like EGR issues, mild MAF problems, and others).
I've done a few of these and while I'm not surprised the exhausts were tight, this is the first time I've seen the intakes that tight. Usually the intakes loosen up and exhaust valves tighten up. Yes, that rear bank is quite the job. My chest is usually pretty sore after leaning over the radiator support for all the time it takes to do that rear bank. It's even worse on the Honda Pilot. One other thing I noticed is that the rear valve cover gasket was blue. From the factory, they're black. Someone had those valve covers off at some point. It wouldn't be out of the norm for the customer to be told the valve cover gaskets are leaking, offer a valve adjustment while in there, and have the valve adjustment declined. I've had that happen to me. Some of the confusion on valve adjustment is caused by how Honda wrote the owners manual and maintenance instructions. The maintenance requirements are a valve adjustment at 105K and at other times if they are noisy. A lot of people, including technicians, think the valves only need to be done if they're noisy. Obviously, that's not the case. I've done these at 105K, when Honda recommends it, and found them right on. By 200K they will be out of spec. I tell people to do the valve adjustment as a maintenance item by 150K. Great scope captures, by the way! Sure wish I had that Pico.
Great point about the gaskets being blue- you are correct- the covers have certainly been off before. not sure if for a timing job or maybe to correct oil leaks. the owners got the car new from dealer in 2012 and have never had valve lash adjusted but I am not sure what other work was done.
@@The_Noticer. That is correct. It's a maintenence item, listed right in the owners manual, that should be done by 150k. 105k is what Honda recommends, which is usually too early but 200k is usually too late.
@@johnaclark1 I have a Honda Accord with a K24A3, and at 200k km (so 125k miles) it was out of spec. I didn't hear anything out of the ordinary, but I just had it done anyway. Luckily on the K24 it's not as horrendous and time consuming to do as the J-series. I also dont need a timing belt job. The benefit of the 4banger :)
I've ran into some older Hondas with valves needing loosening, good to see this reminder again. fuel trims can really help a tech out. I like his method of diagnosing. similar to mine. Friend of mine bought a Honda accord and was showing it off, took it for a test drive and told him it wasn't as fast as it should be. looking into it, someone put a timing belt on and had it one tooth off. after correcting it, he had a smile on his face from ear to ear when he drove it again.
Excellent job. Regarding how your supposed to use tools, I never follow the "rules" it helps me think outside the box. I have used tools the way I like or please for 40 years as a mechanic (including torque wrenches) and I am not stopping now. I approve of how you think.
An interesting observation is that when I had a car in my youth days we only had carb and valve timing to worry about if ones car ran bad; but then checking timing/valve clearence was only a 1/2 hour job jops, even for me! So much for progress.
Love that that diagnosis lead to the correct issue being found. A good way to confirm valve adjustment issue is if the car runs ok when cold and gets worse when warmed up.
I would never have expected a small valve adjustment to make so much difference. Cam phasers, skipped timing belts or chains are more common. Great work!!!!
I agree. I guess I can’t really say how much adjustment there was- I didn’t really measure the adjustment change but some of the valves needed quite a bit of change- others only a little and some were in spec. maybe the variety was more an issue than actual specification?
This same issue happens on the Honda sports bikes too. They call it being "worn in" rather than "worn out, like what is typically said. The valves apparently wear into the aluminum block which will cause the valve stems to stick out longer--- and eventually it will prevent the valves from closing all the way and it will sound like a knock (on the CBR 900's at least), at higher RPM's, like 10k RPM, while you're hard on the throttle.. Because since your exhaust valve isn't closing all the way, you hear the explosion leaking out into the exhaust manifold-- and again, it kinda sounds like a bearing is knocking. Interestingly, there is no "adjustment" on those, but rather, they have little precision ground pucks or discs that push down on the valve stems, and you actually have to pull apart the rocker arms, remove the little discs, put it back together and then measure the lash you need and order those precision pucks in the correct size--- They are about the size of a little coin or a washer-- and they come in 0.001's increments.. I think the numbers are about the same, .008 minimum, .014 max-- or so... And if your clearance is below the 8 thou minimum-- you are supposed to order a down sized puck that will get you back into the tolerance---- typically, you're supposed to order whatever size gets you back to the Max clearance, because over time, it will continue to close the gap again. Very interesting. Another thing you can do if you're cheap, is just grind the end of the valves a bit--- but that's a risky move............................ Also on the sports bikes, I found it interesting: On the crank bearings, you have to "blue print" each one to an exact size. Meaning that you plasti gauge each rod and crank bearing and you have to get it within a .001 tolerance of what the book says.. and they list the bearing sizes by color---- so a std bearing might be .000 red, a .002 over sized is blue, .004 oversized is orange, .006 oversized is purple... ect. ect.. And so you get EACH bearing that precisely fitted--- and when you write them all down and order your bearings, they will come in all the different sizes-- and you'll have to remember where each of the random sizes (and/or color) go-- Rather than say, on a SBC 350 or LS engine rebuild, where you either have all std bearings, or they are all .030" oversized because you got them worked, ect. ect... The entire bank of bearings are all the same----- not the case on a sports bike-- they want each bearing to be PRECISELY fitted so when you are done, they are all EXACTLY at the proper tolerance...... That's what it takes for your engine to go 15k RPM without issues....... Funny enough, All of my bearings were shown to be TOO warn, even for the largest size they offered which was "black, oversized .014" or something like that... (I forget the numbers exactly, but you get the point)--- So I just ordered a full set of the largest bearings they offered all the way across the set and even thought it says I was still slightly out of tolerance and should throw it away--- I figured it was good enough and I put it all back together. Because keep in mind, this was a preventative measure for me-- the bike was running great, and didn't need this done, I just wanted to prevent it ever spinning a bearing--- since it had 30k miles on a 900cc sports bike that I ride like a race car every time I take it out... It held together for years, and eventually I sold it............... I just noticed that most people don't realize or have never heard of the different approach to bearing tolerances on these Japanese bikes-- vs American cars.
That’s better than my theory, valve stem stretch, and valve seats working their way into aluminum is somewhat common but usually results in cracking at some stage
On modern 4 stroke dirtbikes hard starting is the first indicator of valves out of spec and time to adjust. Most people need to rebuild with new seats etc. after 2 adjustments. Modern 4 strokes are revving past 10k rpms for 250s and up to 10k for 450s.
Learned a few years ago that shimmed valves are pretty common on vehicles too, especially in the Japanese segment (but not only Japanese). Though they're mostly the "shim-under-bucket" design, where the "bucket" sits sorta upside-down directly on top of the valve (with the sides of the bucket going around the valve spring), and a shim between the bucket and the valve stem, and the cam is positioned directly above the buckets with the lobes directly contacting them, no rocker arms involved. I've never had the "pleasure" of doing a valve adjustment on one of those engines, but it does seem like a massive pain. And an assorted pack of shims is prohibitively expensive (for what is basically just a bunch of metal discs of a particular thickness), so you really do have to figure out exactly what you need, order them, and then wait for the shipment. And then you have to take the cam out to make the adjustment. I know the Yamaha-designed cylinder heads for the original Ford SHO V6 used them, as well as the venerable redblock Volvo engine, most if not all of the Jaguar XK I6 engines from the 40s to the 90s, and several modern Subaru engines too.
@@stevemarquez9628 makes sense. I've heard that you can run out of adjustment.. But then again, you could just grind the tips of the valves and get more time out of it, as long as your piston rings aren't wrecked.
@@dphoenix1 I've since heard that Toyota has used them also.... They are a bit of a pain; because if they are "too tight", with no clearance and it's sticking the valves open. Then you have to actually take the cam off first, remove all of your shims-- then put the buckets back on with no shims now--- put the cam back on --- and now you'll have a gap that you can measure; and that will get you back to the tolerance that you need.. but then you have to pull the cams off yet again once the new shims come in-- and hopefully you wrote all the sizes down, or you'll be re-measuring yet again to find out where they all go, since they are all different sizes and not a simple standard. So it's quite a "disassemble/ reassemble" dance just to get them measured... I had to do the same on the crank bearings, except with plasti-gauge. fun times
Great job Matt. You are very clear, concise and honest in how you go about your process. We all make some mistakes here and there too, whether it is a DIY or a pro; but as you saw, you cleared up their issue. I have enjoyed your videos along with many other informative CZcams guys and appreciate your years of honest and informative direction. Thank you.
I watch Scotty Kilmer and now you. I am an old(79) IT guy and understand your videos, wish I had known some of the things you posted when I was able to work on cars, and of course had the proper tools(scanner). You are very smart and I wish your shop was near my home, Pennsauken, NJ (Phila area). Thanks for explaining things in a easy to understand mode.
Great video, I do remember 40+ years ago when I was a teenager I did the tappets on my car so they were a bit too tight to try and stop tappet noise, and the result of this was the car was down on power. I think when dealerships come across something like this they are under such time-pressure in the workshop they can afford to spend the time - leading to hope part and swaps. They know they cant bill a customer for 8 hours of diagnosis. HOWEVER given they should have known this was an adjustable tappet engine it may have been worth a stab to do what you have done ! I think the reason the clearances close up is a bit of valve seat erosion due to unleaded fuel.
You're right.. Since they "wear in" -- you need to adjust them to the MAX tolerance-- because they are going to tighten even more over time.. As things "wear out, they get sloppy and loose, ect.. but when things "wear in"--- it's actually the valve seat sinking into the aluminum block; and that's what makes it tighter
I have never “subscribed” to UTUBE anything…EVER…except this guy. I have learned sooo much and I his problem solving and analytical reasoning for each vehicle diagnosis is “superior.” I want to be just as knowledgeable with my 2016 Jeep Patriot. KUDOS and THANK YOU….from John M. (Elmhurst, Pa.)…..I love the “white board of knowledge”!
I completely realize this observation has little to do with the original complaint, but it looks like the engine mounts may need replacement. A friendly observation. I appreciate the video. Also, per the torque wrench use- every tool has a hammer side! haha. Don’t let the chooches get to you, just do your thing…
Great case study from start to finish. awesome to see you starting to use the scope for "working smarter not harder" techniques, one piece of advice as you continue to dive into engine pressure analysis , to check engine mechanical state of health which includes breathing, not just on intake side but exhaust side, it's best to check during cranking intake pulls and exhaust pulses... if engine is mechanically sound, both those sets of waveforms will be the same cylinder to cylinder, if there is a deviation , then there is a mechanical issue, valve adjustment would be "seen" thru this cranking testing. I've done plenty of case studies using these methods and then some and explain lots of the theory, if you get a chance watch them all and feel free to contact me for any advice or guidance into this new venture of transducer testing and engine pressure waveform analysis. Again, great job and thank you for sharing.
Skills! Shows the science wins every time 😂 I wonder what Eric the Car Guy would say, as I think he said the V6 rarely needs adjustment... That engine you worked on looked pretty clean for those miles.
@@AlCatrraz I believe he was talking about under valve covers, looking clean. I thought the same. Regular (quality) oil (not parts) changes probably, eh ?
You know, your videos are some of the best reasons to get an electric car. I know they will have their own problems, but I hope there will be less , and maybe easier to diagnose.
i really like that pressure transducer. i have performed compression tests and have learned about cylinder leakage tests. i for sure am blown away pun intended by how you can observe the pressure at different segments of the cycle and thus point towards the valves issue. really really fascinating. and it would sound more like it would show intake data vs exhaust but a vacuum gauge i know can show valve problems and timing etc and theres a whole chart. when you prior to opening the lid said valves being too tight would make sense i said yep
That is an interesting video. As a former professional mechanic I had only seen that procedure done maybe 5 times in 5 years and only on a specific Toyota engine. The mechanic who had regular Toyota customers would on occasion recommend that service on 80's and 90's 4 cylinder pickup trucks, he would listen for it maybe during other service like an oil change. We never even had to worry about it on GM or Ford or Jeep vehicles. I am surprised that the valve adjustment was not checked when the timing belt service was done or caught by the dealer. But again not common and maybe the younger techs would not even know about that valve setup. Nice diagnosis, great channel.
As a DIY guy who has owned several Hondas, valve adjustment is a maintenance issue that shouldn't wait until there is a problem. As others have said, It's something that you should do when you're doing the timing belt, or changing a leaky gasket. Sometimes "might as well do ???" while you are there is the right approach. Hondas aren't the only engines that need the valve adjusted. Awesome work, I've just started to up my diagnostic game, and I've learned a lot from you already.
Great diagnosis Matt. I almost discounted valve adjustment at first as I know its a maintainance item on these engines. I was inclined towards a warped lobe on the camshaft - Ivan and Eric O saw a Hyundai with this issue many years ago. Valve adjustment is much better for the customer... Shocking how many garages it went through before someone diagnosed it. I wouldn't call valve adjustment rocket surgery.
Very good diagnostic! I do have to say that I am at a shock that shops did look at valve lash. Anyone who knows Honda engines should recognize that the symptoms pointed in that direction. Keep up the good work!
Excellent series. I will now go back and watch your other diagnostic video(s) on how to check valve timing without becoming pimped by a customer who got a "sweet" deal at a car auction.
Hahahaha funny you mention that. my earliest videos very often featured “auction vehicles”. Some of which I bought myself because at the time I didn’t have a customer base yet to get cars in consistently to make videos.
Very nice work and great explanation. Bravo! Highlights the importance of following the service schedule too. If you look after things they look after you.
I am not a mechanic... just like to learn ALL KIND OF THINGS ... What I liked is your saying THINK INDEPENDENTLY.... ALWAYS USE LOGIC... This is THE ESSENSE of INDIVIDUALISM and our HUMAN RIGHTS are INDIVIDUAL RIGHTS and not COMMUNAL RIGHTS! Good video
Right this goes back to old school mechanic’s before auto valve tappipts set with oil pressure, and do you realise that you’ve saved this engine from burning out the valves because all valves do recess/ recede into the head to a point where they don’t close which in turn leads to the valves being burnt out , so you’ve saved the owners a lot of money for the future apart from fixing their car well done brilliant video and well thought through with logic
ALL Honda's both 4 and 6 cylinder still have valve adjustments to this day! (105,000 mile interval) Good Job on the diag, I've used map voltage in the past to get to the valves being tight, a reading over .95 volts (running at idle, warmed up engine) means tight valves in Honda world. .88 volts is closer to normal (with OEM Map sensor)
Hi I realy enjoy your 1 video and 2 as well and i congratulate you been the Mr. fix it after all the parts replacing mechanics,with out checking first the sine of one or two cylinder, BRAVO.
Great video. I seen this problem on a few cars many years ago. Great troubleshooting. Always Great to see a technician not throw the parts that's not needed . Azzhats mechanics. Also I got a laugh about the torque wrench. I was a auto mechanic for over 40 years. Disabled now. I sure enjoy your videos. Thanks for posting them on here.
Nice Job. I like the way you approach the problem to diagnostic it. I was thinking the same thing that you should have taking the pressure of multiple cylinder and not just one, because it could happen that the one you test was fine and the other, but you mentioned it when you talked about the mistake you made. I love to troubleshoot problems, and I learn a lot every time i watch one of this troubleshooting with detail of how to do test. Great job.
I ran into a similar issue on a Honda Pilot about a year ago, although mine was much easier to diagnose. Only one cylinder had bad valve lash, so you could hear the lack of (relative) compression in the one cylinder when cranking it. I could definitely see how others before you had failed. Since it was ALL of the cylinders, the engine wouldn't have sounded off in the first place.
Job well done, Matt. I'm still amazed by the fact that the previous workshops disregarded valve adjustment, with hondas they are some kind of main course meal 😂
I like the logic you've employed to get to your solution. If you are the owner reading this... you can thank Mr. Schrodinger for saving you the cost of a valve job since the exhaust valves were likely close to being burned. Makes me wonder if the valves were adjusted or not, prior to the valve cover being removed (i.e. open the box ;) )
Great diagnostic, as for the torque wrench, I use it if I have it out but I suppose if you use it all the time instead of a wrench it could cause problems, but only problem I have had is not slacking the spring after use. We got lot's of tight values when the lead was removed from fuel valves sinking into the head.
Not a naysayer, I love your channel. I think the argument against using a torque wrench is this: with my torque wrench, if you switch the ratcheting pawl to loosen, the "clicking" feature is disabled. This opens the possibility for the user to surpass the maximum torque rating of the torque wrench. Additionally, it opens the possibility for the user to use the torque wrench as a breaker bar because of how much leverage the torque wrench provides. In your application today, you are neither loosening nor exceeding the limit of the torque wrench, so neither of those apply. One last hint of an argument might be that you have to set the torque pretty high on your wrench to use it as a ratchet, and leaving it set high over long periods of time can affect calibration. Just some thoughts
Good video Matt. It often turns out to be things people ignore. Great catch. Remember, every tool is also a hammer. Torque on friend. Take that trolls.
i have a craftsman 250 ft/lb click type torque wrench. Its 28" long and very comfortable to use to undo the 160 ft/lb brake caliper bracket bolts on my van. I just wouldnt use it maliciously and stomp on it to remove a neighbors stuck overtightened lugnuts or on bolts under the frame that require a breaker bar or pistol, or heat etc
Oh Man! Your Awesome! Tell these people how it is and how it goes. Love it! Keep up the great Vids fella. Thank you for your point of view on scientific diagnosis.
Wow! great case study Matt! I can't believe the dealer missed that, they usually recommend it for everything, even when you don't need it. Brandon Steckler has a class on in cylinder waveforms and he proves tight valves with a pulse sensor in the exhaust , you can see the valve overlap is different.
Valve adjustment is actually still a thing, it was only during the era of hydraulic lifters it wasn't. But with hard metal seats and valves it's rarer. On a Subaru one indicator for valve clearance adjustment needed is misfires. A compression test doesn't necessarily indicate that the that the clearance is too tight since the valve stems extends a bit due to heat when the engine is running.
Crazy how they didn't do the valve adjustment with the timing belt job, that's standard operation procedure on those engines. In either case, solid video series...thanks for sharing this with us! I understand your frustration with people who always have something clever to say too, you are absolutely right about it not hurting that torque wrench. No matter what a guy does to help others, there's always someone in the world (likely jealous or having personal life issues) trying to unload their hate on us 😂...all you can do is laugh at the ridiculousness of it all. Keep on keeping on Matt!
Thanks man. in all fairness- *I* would have also done a timing belt without valve adjustment too because I had absolutely no idea these cars- or ANY car of the year would need a valve adjustment until this video!!
Unbolt the upper motor mount and if there is one in the front. Take a ratchet strap hook it to something solid on top of the engine. Hook the other end to something solid in front of the car like a tool box, ratchet the top of the engine forward a bit, bam rear valves now accessable.
Easiest way I found to see if valves need adjusting is with the car running. Place a large piece a paper against the exhaust tip. If there is vacuum or the exhaust is pulling the paper the valves are out of adjustment. Big time saver!!
Never ignore oil either. I put some cheap supermarket oil in turbo diesel. It dragged the turbo, car struggled to accelerate. So drained and put some better quality oil in, runs great now.
I enjoyed this video. Thanks for going back in cylinder with the pressure transducer to show the difference. I really appreciate the visual comparison. (Perhaps it is time to add a pressure transducer to my Pico kit.) I know you advocate against it, but similar to changing a timing belt every X number of miles, the valve clearances on the Honda 3.5 V6 and the the 4 cylinder should be checked once the vehicle is over 120K miles. I'm just a DIYer, and it is only anecdotal evidence, but I have checked valve clearances on two 3.5s and one 4 cylinder engine that had exceeded 120k miles and they were all out of spec. Each of these engines had valve clearance issues similar to your findings-- too tight. One of the vehicles, a Honda MDX with 160K miles, had intermittent misfires and driveability issues that a shop couldn't resolve so my buddy asked me if I could take a look at it. The valve adjustment cured the misfires and the vehicle has been running great.
I’m surprised they didn’t burn a valve after driving it this way for so long. If the valves are too tight, they hang open, and the thinner edges on the valves will get very hot and melt.
I always adjusted valves to the higher clearance for a cold engine and the lower end of a warm engine and I have been told that valve clearance will be zero backlash when 9is at operating temperatures
It is always a good idea to confirm the clearance right after you adjust it. Even when holding the threaded adjuster with a screwdriver, that final push of the locknut seems to turn the adjuster just a hair tighter. At least that's how I remember my old 1792 CB750 K, and before that, the little XR75 trail bike. P.S., a leakdown test would also have pointed you to valve clearances too tight causing leaking into the intake and or exhaust.
Great video. I knew about valves getting looser over time, but never had heard about them getting tighter. I had to do search on that to understand why. From what I read, it is because of valve seat wear. While it was outside the scope of what you were trying to fix, it might have been educational to borescope the cylinders to see what the condition of the valves were. It is possible that a valve job is is not too far off for the car.
I just replaced the head gaskets on a single overhead cam Subaru boxer engine with 180000 miles that was very very clean inside--good oil change intervals, basically. Every valve was at minimum clearance or too tight.
Usually valves that are adjustable is adjusted during a timing belt replacement. The key that led to valves being to tight no codes. The sensor readings especially fuel trims show rich. Tight valves keeps them slightly open when hot. Still tough to diagnose I can't understand why a fuel pump or any other sensors were replaced for nothing. I thought a leaking injector would be the cause. Great job, like to see mechanics at work.
Nice job it sad Honda dealer missed that especially when it recommend that service is done during timing belt intervals as well. It is very common problem that need done on higher mileage v6 3.5. Owned a Honda 2007 Pilot and only thing needed done that ran into during own it.
I would suspect that the compression is a little higher. And surprisingly there was not pop back in the intake side. So My question is this engine had problems for years. Were they out of adjustment from the factory or a result from the valves and seats wearing in . Amazing it ran as well as it did before. I work on a lot of small engines a UTV's such small things can cause big performance issues. Good job
Great job! I am constantly telling others that I break mechanics down into two categories: parts changers and troubleshooters. And unfortunately, you still see a lot of parts changers even at the dealerships. I also have a saying: Does that mechanic have 10 years worth of experience, or 1 year of experience that they have held for 10 years?
hahah had this video playing in the background .. you got me hooked now bro .. hahaha part 2 !! lets do it ! i resently had a 2000 honda accord i did a valve adjustment on 4 cylinder .. glad you found the issue .. bet customers happy
To tight valves. The valves cupped? I have seen that once on a diesel that maybe effected how it ran. Those engines were junk. Rare valve adjustment does much for noticeable engine power. They usually wear loose. Mostly a preventative maintenance thing to help prevent valve train wear. I never had a pico or pressure transducer 15 years ago to even think of that test. Love it. Good work.
200k of metal to metal beating against each other. Valve tightens up because the metal gives a little (sinking the valve), especially with the exhaust due to the high heat.
Tight valves are the silent killer...expecially exhaust valves in the first gen CRV's. Loose valves make noise, can lead to reduced power but realistically cannot cause further damage. Tight exhaust valves lead to burnt valves and in the example above, mystery idle code that is almost the only thing that (somewhat) regularly kills that particular engine even if it can be driven with that code for quite a while if you do not have mandatory emissions testing.
Honda Fit also requires manual valve adjustments periodically. Angled feeler gauges are your friend. I found that the valves required more adjusting at the first service interval; less so on later ones.
totally agree. reason being is that during break-in there may be give or take in the cam lobes, roller rockers, valves, etc that would make the initial factory setting to become out of spec even when it was right at the first place. I have a Fit also (it's named Jazz here) and did valve adj 9,000 miles on the clock. massive difference, car runs smooth n powerful.
@@1_D333 Honda is or was, a big believer in non-hydraulic valves for a long time. usually with a four valve engine, they recommend using two feeler gauges on both valves opened by a forked rocker arm. Just like on the four valve motorcycle engines........ Guess Honda techs 'forgot' that, most get checked every 17.5K miles. Easy to forget till you do & it runs like poo. Time for a valve clearance check.
Usually valves get loose, if they are getting tight it could very well be a sign of valve stem stretch, and things can only stretch so much before they break
Was at a metal working class yesterday and the horizontal bandsaw needed an angle adjustment (for the newer person in the class). Instructor goes to the board, pulls off an adjustable wrench and proceeds to explain how to use it. (new person has no shop experience). I mention something about needing to check whether it was metric or standard, and the instructor starts to look at the wrench handle. Now, either he was too smooth in admitting he fell for it, or he was looking for a smooth way out, but he mumbles something about that, and then saying it wouldn't matter a few seconds later.
Honda K-series 4 cylinders need valve lash adjustment as well. My brother and I talked about doing it on his element, but now I'm thinking it would be worth getting an in-cylinder pressure transducer to see if that's even necessary. I'll be going with Ivan's pressure transducer though, the pico is mighty expensive.
it drives perfect because of all the parts that were replaced before you by others. You don't deserve all the credit so don't forget to thank them. Go Scotty !
The naysayers are just looking for attention online. It does nothing to the wrench. Tight exhaust valves actually super common on Honda J motors. Done dozens and dozens of 03-06 MDX valve adjustments for high map voltage and rich trims coupled with random misses(dealer tech). Kudos to your method of proving it with in cylinder testing though!
The last car I adjusted valves on was an 85 300SD Mercedes 5 cylinder, over 30 yrs. ago. Excellent diagnosis!! The scientific method rules the universe, so why not your car?!!!
Well done. I took my 2000 Honda S2000 to the same mechanic for six years and he laughed at me when I asked him when he last adjusted the valve clearances. He stopped laughing and apologised when I showed him the manual. The car ran a lot better after that service. If you are a professional mechanic why would you assume things when there is so much information readily available on the internet? Like you say, it can save the customer a lot of time and money if you just spend a little effort learning the car, at least pull up a service sheet!
Great story and helps explain why dealer missed this.
@andyoverall1951, did you fire you mechanic after you proved him wrong for laughing at you?
@@tmph1814 lol, I just quietly moved on to another mechanic.
@andyoverall1951 yes a mother mechanic that doesn't realize the importance of reading the service manual the former mechanic has atheist be introduced to the idea that maybe he should if read service manual
In the 70's, a valve adjustment was always included with a major tune up in my shop. Of course the engines were 4 cylinders and easy to get the covers off. A minor tune up would have been plugs, points and condenser (what are those?), carb throat and linkage cleaning, pcv system maintenance and an air filter. Finally, timing, idle speed and fuel mixture adjustment. Of course I had an oscilloscope and used it for every tune up major and minor. A minor tune was recommended at 10k intervals and major at 50k. Timing belts at 70k and chains at 100k. Saw too many chains sawing their way through timing covers.
The best ones were Pontiacs around 1969 or 1970 . The Pop Corn Machines . On the V8's , the cam lobes , I believe exhaust , were defective and rounded down . When the intake opened , it blew back out of the carburetor . My friend's popped for a few weeks . Then when it wouldn't start , we opened the hood . The carburetor wes blown off the manifold and hanging by the steel fuel line ! I put in a new cam , lifters , STEEL timing gears and chain .
Seen a few sawings too and very worn and I'm not a mechanic. Had room to work though
I just can’t get enough of your channel. I really appreciate you sharing the information with the masses. Keep doing the fantastic job you’re doing.
It's easy to see why valve lash adjustment is part of the routine maintenance schedule. Getting the diagnosis is not easy, especially in mild cases! Many shops won't have the time or tools to measure in-cylinder pressure readings. Also with VVT involved, those waveforms may change depending on rpm, ambient temp, engine temp, etc. Good for you to make the diagnosis accurately. For all else, respect and follow the maintenance schedule. This has to be added to my list of 'sleeper diagnoses' that don't show up on a scan tool (like EGR issues, mild MAF problems, and others).
I've done a few of these and while I'm not surprised the exhausts were tight, this is the first time I've seen the intakes that tight. Usually the intakes loosen up and exhaust valves tighten up. Yes, that rear bank is quite the job. My chest is usually pretty sore after leaning over the radiator support for all the time it takes to do that rear bank. It's even worse on the Honda Pilot.
One other thing I noticed is that the rear valve cover gasket was blue. From the factory, they're black. Someone had those valve covers off at some point. It wouldn't be out of the norm for the customer to be told the valve cover gaskets are leaking, offer a valve adjustment while in there, and have the valve adjustment declined. I've had that happen to me.
Some of the confusion on valve adjustment is caused by how Honda wrote the owners manual and maintenance instructions. The maintenance requirements are a valve adjustment at 105K and at other times if they are noisy. A lot of people, including technicians, think the valves only need to be done if they're noisy. Obviously, that's not the case. I've done these at 105K, when Honda recommends it, and found them right on. By 200K they will be out of spec. I tell people to do the valve adjustment as a maintenance item by 150K.
Great scope captures, by the way! Sure wish I had that Pico.
If you are a shop owner, get it, if not, just get a cheap scope, they do the same job.
Great point about the gaskets being blue- you are correct- the covers have certainly been off before. not sure if for a timing job or maybe to correct oil leaks. the owners got the car new from dealer in 2012 and have never had valve lash adjusted but I am not sure what other work was done.
I'd say you always have to do it, because noisy valves are only when they're too loose. iirc they dont make excessive noise when they're too tight.
@@The_Noticer. That is correct. It's a maintenence item, listed right in the owners manual, that should be done by 150k. 105k is what Honda recommends, which is usually too early but 200k is usually too late.
@@johnaclark1 I have a Honda Accord with a K24A3, and at 200k km (so 125k miles) it was out of spec. I didn't hear anything out of the ordinary, but I just had it done anyway. Luckily on the K24 it's not as horrendous and time consuming to do as the J-series. I also dont need a timing belt job. The benefit of the 4banger :)
I've ran into some older Hondas with valves needing loosening, good to see this reminder again. fuel trims can really help a tech out. I like his method of diagnosing. similar to mine.
Friend of mine bought a Honda accord and was showing it off, took it for a test drive and told him it wasn't as fast as it should be. looking into it, someone put a timing belt on and had it one tooth off. after correcting it, he had a smile on his face from ear to ear when he drove it again.
I would like to see a follow-up video showing the customer's reaction. Also, how many hours were you able to bill the customer, etc.
Excellent job. Regarding how your supposed to use tools, I never follow the "rules" it helps me think outside the box. I have used tools the way I like or please for 40 years as a mechanic (including torque wrenches) and I am not stopping now. I approve of how you think.
An interesting observation is that when I had a car in my youth days we only had carb and valve timing to worry about if ones car ran bad; but then checking timing/valve clearence was only a 1/2 hour job jops, even for me! So much for progress.
Plus adjusted the points in the distributor beside the road. LOL
Love that that diagnosis lead to the correct issue being found. A good way to confirm valve adjustment issue is if the car runs ok when cold and gets worse when warmed up.
I would never have expected a small valve adjustment to make so much difference.
Cam phasers, skipped timing belts or chains are more common.
Great work!!!!
I agree. I guess I can’t really say how much adjustment there was- I didn’t really measure the adjustment change but some of the valves needed quite a bit of change- others only a little and some were in spec. maybe the variety was more an issue than actual specification?
Great job dude! even at a dealerships most are clueless! You,re a true critical thinker! Not many like you!
I appreciate that!
Thank You Matt, I'm a DIY and not having those diagnostics tools, your videos help me a lot to understand how engine works and fix it.
Great to hear!
This same issue happens on the Honda sports bikes too. They call it being "worn in" rather than "worn out, like what is typically said. The valves apparently wear into the aluminum block which will cause the valve stems to stick out longer--- and eventually it will prevent the valves from closing all the way and it will sound like a knock (on the CBR 900's at least), at higher RPM's, like 10k RPM, while you're hard on the throttle.. Because since your exhaust valve isn't closing all the way, you hear the explosion leaking out into the exhaust manifold-- and again, it kinda sounds like a bearing is knocking. Interestingly, there is no "adjustment" on those, but rather, they have little precision ground pucks or discs that push down on the valve stems, and you actually have to pull apart the rocker arms, remove the little discs, put it back together and then measure the lash you need and order those precision pucks in the correct size--- They are about the size of a little coin or a washer-- and they come in 0.001's increments.. I think the numbers are about the same, .008 minimum, .014 max-- or so... And if your clearance is below the 8 thou minimum-- you are supposed to order a down sized puck that will get you back into the tolerance---- typically, you're supposed to order whatever size gets you back to the Max clearance, because over time, it will continue to close the gap again. Very interesting. Another thing you can do if you're cheap, is just grind the end of the valves a bit--- but that's a risky move............................
Also on the sports bikes, I found it interesting: On the crank bearings, you have to "blue print" each one to an exact size. Meaning that you plasti gauge each rod and crank bearing and you have to get it within a .001 tolerance of what the book says.. and they list the bearing sizes by color---- so a std bearing might be .000 red, a .002 over sized is blue, .004 oversized is orange, .006 oversized is purple... ect. ect.. And so you get EACH bearing that precisely fitted--- and when you write them all down and order your bearings, they will come in all the different sizes-- and you'll have to remember where each of the random sizes (and/or color) go-- Rather than say, on a SBC 350 or LS engine rebuild, where you either have all std bearings, or they are all .030" oversized because you got them worked, ect. ect... The entire bank of bearings are all the same----- not the case on a sports bike-- they want each bearing to be PRECISELY fitted so when you are done, they are all EXACTLY at the proper tolerance...... That's what it takes for your engine to go 15k RPM without issues.......
Funny enough, All of my bearings were shown to be TOO warn, even for the largest size they offered which was "black, oversized .014" or something like that... (I forget the numbers exactly, but you get the point)--- So I just ordered a full set of the largest bearings they offered all the way across the set and even thought it says I was still slightly out of tolerance and should throw it away--- I figured it was good enough and I put it all back together. Because keep in mind, this was a preventative measure for me-- the bike was running great, and didn't need this done, I just wanted to prevent it ever spinning a bearing--- since it had 30k miles on a 900cc sports bike that I ride like a race car every time I take it out... It held together for years, and eventually I sold it............... I just noticed that most people don't realize or have never heard of the different approach to bearing tolerances on these Japanese bikes-- vs American cars.
That’s better than my theory, valve stem stretch, and valve seats working their way into aluminum is somewhat common but usually results in cracking at some stage
On modern 4 stroke dirtbikes hard starting is the first indicator of valves out of spec and time to adjust. Most people need to rebuild with new seats etc. after 2 adjustments. Modern 4 strokes are revving past 10k rpms for 250s and up to 10k for 450s.
Learned a few years ago that shimmed valves are pretty common on vehicles too, especially in the Japanese segment (but not only Japanese). Though they're mostly the "shim-under-bucket" design, where the "bucket" sits sorta upside-down directly on top of the valve (with the sides of the bucket going around the valve spring), and a shim between the bucket and the valve stem, and the cam is positioned directly above the buckets with the lobes directly contacting them, no rocker arms involved. I've never had the "pleasure" of doing a valve adjustment on one of those engines, but it does seem like a massive pain. And an assorted pack of shims is prohibitively expensive (for what is basically just a bunch of metal discs of a particular thickness), so you really do have to figure out exactly what you need, order them, and then wait for the shipment. And then you have to take the cam out to make the adjustment.
I know the Yamaha-designed cylinder heads for the original Ford SHO V6 used them, as well as the venerable redblock Volvo engine, most if not all of the Jaguar XK I6 engines from the 40s to the 90s, and several modern Subaru engines too.
@@stevemarquez9628 makes sense. I've heard that you can run out of adjustment.. But then again, you could just grind the tips of the valves and get more time out of it, as long as your piston rings aren't wrecked.
@@dphoenix1 I've since heard that Toyota has used them also.... They are a bit of a pain; because if they are "too tight", with no clearance and it's sticking the valves open. Then you have to actually take the cam off first, remove all of your shims-- then put the buckets back on with no shims now--- put the cam back on --- and now you'll have a gap that you can measure; and that will get you back to the tolerance that you need.. but then you have to pull the cams off yet again once the new shims come in-- and hopefully you wrote all the sizes down, or you'll be re-measuring yet again to find out where they all go, since they are all different sizes and not a simple standard. So it's quite a "disassemble/ reassemble" dance just to get them measured... I had to do the same on the crank bearings, except with plasti-gauge. fun times
Great job Matt. You are very clear, concise and honest in how you go about your process. We all make some mistakes here and there too, whether it is a DIY or a pro; but as you saw, you cleared up their issue. I have enjoyed your videos along with many other informative CZcams guys and appreciate your years of honest and informative direction. Thank you.
I appreciate that comment very much!! Thank you!!
This repair was great. Very educational, especially about timing and how engine(pistons and valve really works). Thanks again !
I watch Scotty Kilmer and now you. I am an old(79) IT guy and understand your videos, wish I had known some of the things you posted when I was able to work on cars, and of course had the proper tools(scanner). You are very smart and I wish your shop was near my home, Pennsauken, NJ (Phila area). Thanks for explaining things in a easy to understand mode.
Congratulations on the transition!!! Maybe it will inspire to start up again!!
Awesome video. Goes to show that even newer engines have some of the same concepts as older ones, including valve adjustment.
Great video, I do remember 40+ years ago when I was a teenager I did the tappets on my car so they were a bit too tight to try and stop tappet noise, and the result of this was the car was down on power. I think when dealerships come across something like this they are under such time-pressure in the workshop they can afford to spend the time - leading to hope part and swaps. They know they cant bill a customer for 8 hours of diagnosis. HOWEVER given they should have known this was an adjustable tappet engine it may have been worth a stab to do what you have done ! I think the reason the clearances close up is a bit of valve seat erosion due to unleaded fuel.
You're right.. Since they "wear in" -- you need to adjust them to the MAX tolerance-- because they are going to tighten even more over time.. As things "wear out, they get sloppy and loose, ect.. but when things "wear in"--- it's actually the valve seat sinking into the aluminum block; and that's what makes it tighter
This is a great series Matt and it encourages me to not give up on figuring my no start condition out on my first car. Good point on the torque wrench
I have never “subscribed” to UTUBE anything…EVER…except this guy. I have learned sooo much and I his problem solving and analytical reasoning for each vehicle diagnosis is “superior.” I want to be just as knowledgeable with my 2016 Jeep Patriot. KUDOS and THANK YOU….from John M. (Elmhurst, Pa.)…..I love the “white board of knowledge”!
Thank you so much, what a great comment!!!
I completely realize this observation has little to do with the original complaint, but it looks like the engine mounts may need replacement. A friendly observation. I appreciate the video. Also, per the torque wrench use- every tool has a hammer side! haha. Don’t let the chooches get to you, just do your thing…
I watch a lot of these videos but this is my first on this channel. I just learned so much about valve timing. Thanks for the great explanation.
Welcome aboard! This is how we do things on the bright side of CZcams lol
Great case study from start to finish. awesome to see you starting to use the scope for "working smarter not harder" techniques, one piece of advice as you continue to dive into engine pressure analysis , to check engine mechanical state of health which includes breathing, not just on intake side but exhaust side, it's best to check during cranking intake pulls and exhaust pulses... if engine is mechanically sound, both those sets of waveforms will be the same cylinder to cylinder, if there is a deviation , then there is a mechanical issue, valve adjustment would be "seen" thru this cranking testing. I've done plenty of case studies using these methods and then some and explain lots of the theory, if you get a chance watch them all and feel free to contact me for any advice or guidance into this new venture of transducer testing and engine pressure waveform analysis. Again, great job and thank you for sharing.
Great advice!! Thank you!
Skills! Shows the science wins every time 😂 I wonder what Eric the Car Guy would say, as I think he said the V6 rarely needs adjustment... That engine you worked on looked pretty clean for those miles.
Because they replaced everything....
@@AlCatrraz I believe he was talking about under valve covers, looking clean. I thought the same. Regular (quality) oil (not parts) changes probably, eh ?
You know, your videos are some of the best reasons to get an electric car. I know they will have their own problems, but I hope there will be less , and maybe easier to diagnose.
i really like that pressure transducer. i have performed compression tests and have learned about cylinder leakage tests. i for sure am blown away pun intended by how you can observe the pressure at different segments of the cycle and thus point towards the valves issue.
really really fascinating.
and it would sound more like it would show intake data vs exhaust but a vacuum gauge i know can show valve problems and timing etc and theres a whole chart.
when you prior to opening the lid said valves being too tight would make sense i said yep
That is an interesting video. As a former professional mechanic I had only seen that procedure done maybe 5 times in 5 years and only on a specific Toyota engine. The mechanic who had regular Toyota customers would on occasion recommend that service on 80's and 90's 4 cylinder pickup trucks, he would listen for it maybe during other service like an oil change. We never even had to worry about it on GM or Ford or Jeep vehicles. I am surprised that the valve adjustment was not checked when the timing belt service was done or caught by the dealer. But again not common and maybe the younger techs would not even know about that valve setup. Nice diagnosis, great channel.
Thanks so much for stopping by!!
As a DIY guy who has owned several Hondas, valve adjustment is a maintenance issue that shouldn't wait until there is a problem. As others have said, It's something that you should do when you're doing the timing belt, or changing a leaky gasket. Sometimes "might as well do ???" while you are there is the right approach. Hondas aren't the only engines that need the valve adjusted. Awesome work, I've just started to up my diagnostic game, and I've learned a lot from you already.
No, if you hear a problem, you wanna get it done before it comes into a big problem before it goes into major issues.
I would just pull valve cover to just check it out.
Nice diagnosis & repair Matt! Valve lash definitely affects valve timing & compression issues & Honda is notorious for it!
I do exactly what you do, when it comes to diagnosis of vehicles. Bravo my friend
Great diagnosis Matt.
I almost discounted valve adjustment at first as I know its a maintainance item on these engines. I was inclined towards a warped lobe on the camshaft - Ivan and Eric O saw a Hyundai with this issue many years ago. Valve adjustment is much better for the customer... Shocking how many garages it went through before someone diagnosed it. I wouldn't call valve adjustment rocket surgery.
Very good diagnostic!
I do have to say that I am at a shock that shops did look at valve lash. Anyone who knows Honda engines should recognize that the symptoms pointed in that direction.
Keep up the good work!
Will do!!
Excellent series. I will now go back and watch your other diagnostic video(s) on how to check valve timing without becoming pimped by a customer who got a "sweet" deal at a car auction.
Hahahaha funny you mention that. my earliest videos very often featured “auction vehicles”. Some of which I bought myself because at the time I didn’t have a customer base yet to get cars in consistently to make videos.
Hey it's a valid business seam if you got the right stuff.
Very nice work and great explanation. Bravo!
Highlights the importance of following the service schedule too. If you look after things they look after you.
Very true!! I didn’t even know this was regular maintenance until this video to be honest though lol
You are one of the very few.honest and just Technician ive come across.god blesses greatly honest people like you.👍👍🙏🙏
I am not a mechanic... just like to learn ALL KIND OF THINGS ...
What I liked is your saying THINK INDEPENDENTLY.... ALWAYS USE LOGIC...
This is THE ESSENSE of INDIVIDUALISM and our HUMAN RIGHTS are INDIVIDUAL RIGHTS and not COMMUNAL RIGHTS!
Good video
Right this goes back to old school mechanic’s before auto valve tappipts set with oil pressure, and do you realise that you’ve saved this engine from burning out the valves because all valves do recess/ recede into the head to a point where they don’t close which in turn leads to the valves being burnt out , so you’ve saved the owners a lot of money for the future apart from fixing their car well done brilliant video and well thought through with logic
ALL Honda's both 4 and 6 cylinder still have valve adjustments to this day! (105,000 mile interval) Good Job on the diag, I've used map voltage in the past to get to the valves being tight, a reading over .95 volts (running at idle, warmed up engine) means tight valves in Honda world. .88 volts is closer to normal (with OEM Map sensor)
Hi I realy enjoy your 1 video and 2 as well and i congratulate you been the Mr. fix it after all the parts replacing mechanics,with out checking first the sine of one or two cylinder, BRAVO.
Great video. I seen this problem on a few cars many years ago. Great troubleshooting. Always Great to see a technician not throw the parts that's not needed . Azzhats mechanics. Also I got a laugh about the torque wrench. I was a auto mechanic for over 40 years. Disabled now. I sure enjoy your videos. Thanks for posting them on here.
Thanks for watching!!
Nice Job. I like the way you approach the problem to diagnostic it. I was thinking the same thing that you should have taking the pressure of multiple cylinder and not just one, because it could happen that the one you test was fine and the other, but you mentioned it when you talked about the mistake you made. I love to troubleshoot problems, and I learn a lot every time i watch one of this troubleshooting with detail of how to do test. Great job.
Thanks 👍.
Brilliant diagnosis and fix, Matt.
That must have felt good. 😊
It did!! total satisfaction when you solve a puzzle
when the timing belt was done that would be the time to adjust valves the car would have been fixed then. Great job I enjoy your videos
Yeah I agree- and in fact the service manual says as much too.
I ran into a similar issue on a Honda Pilot about a year ago, although mine was much easier to diagnose. Only one cylinder had bad valve lash, so you could hear the lack of (relative) compression in the one cylinder when cranking it. I could definitely see how others before you had failed. Since it was ALL of the cylinders, the engine wouldn't have sounded off in the first place.
Wish we get to see the customer reaction I bet they were soooooo happy ! Nice work and thanks for the education.
You can bet they were happy!!
Job well done, Matt. I'm still amazed by the fact that the previous workshops disregarded valve adjustment, with hondas they are some kind of main course meal 😂
I like the logic you've employed to get to your solution. If you are the owner reading this... you can thank Mr. Schrodinger for saving you the cost of a valve job since the exhaust valves were likely close to being burned. Makes me wonder if the valves were adjusted or not, prior to the valve cover being removed (i.e. open the box ;) )
Great diagnostic, as for the torque wrench, I use it if I have it out but I suppose if you use it all the time instead of a wrench it could cause problems, but only problem I have had is not slacking the spring after use. We got lot's of tight values when the lead was removed from fuel valves sinking into the head.
Not a naysayer, I love your channel. I think the argument against using a torque wrench is this: with my torque wrench, if you switch the ratcheting pawl to loosen, the "clicking" feature is disabled. This opens the possibility for the user to surpass the maximum torque rating of the torque wrench. Additionally, it opens the possibility for the user to use the torque wrench as a breaker bar because of how much leverage the torque wrench provides.
In your application today, you are neither loosening nor exceeding the limit of the torque wrench, so neither of those apply.
One last hint of an argument might be that you have to set the torque pretty high on your wrench to use it as a ratchet, and leaving it set high over long periods of time can affect calibration. Just some thoughts
Respect, nice to see somebody that goes back to first princilples
The way you do things is what you have found to work. options are like assholes everybody has one. I admire the knowledge you show on these videos.
Im surprised you didn’t have any misfire codes with the valves so tight... very common issue with this engine 😊
Good video Matt. It often turns out to be things people ignore. Great catch. Remember, every tool is also a hammer. Torque on friend. Take that trolls.
i have a craftsman 250 ft/lb click type torque wrench. Its 28" long and very comfortable to use to undo the 160 ft/lb brake caliper bracket bolts on my van. I just wouldnt use it maliciously and stomp on it to remove a neighbors stuck overtightened lugnuts or on bolts under the frame that require a breaker bar or pistol, or heat etc
Oh Man! Your Awesome! Tell these people how it is and how it goes. Love it! Keep up the great Vids fella. Thank you for your point of view on scientific diagnosis.
Wow! great case study Matt! I can't believe the dealer missed that, they usually recommend it for everything, even when you don't need it. Brandon Steckler has a class on in cylinder waveforms and he proves tight valves with a pulse sensor in the exhaust , you can see the valve overlap is different.
Thanks man. Yes I saw his video- it was how I learned cylinder waveforms. guy is a genius.
@@SchrodingersBox Yes he definitely is a genius. I watched his class then bought his book, then dropped $1000 on a wps500;)
@@SchrodingersBox Yes he definitely is a genius. I watched his class then bought his book, then dropped $1000 on a wps500;)
I just mentioned that on the first video a minute ago. Brandon has before and after pictures in his book on this exact engine
It's how you found the problem that actually makes it stand out. It truly was a great diag from start to finish.
Valve adjustment is actually still a thing, it was only during the era of hydraulic lifters it wasn't. But with hard metal seats and valves it's rarer.
On a Subaru one indicator for valve clearance adjustment needed is misfires.
A compression test doesn't necessarily indicate that the that the clearance is too tight since the valve stems extends a bit due to heat when the engine is running.
Crazy how they didn't do the valve adjustment with the timing belt job, that's standard operation procedure on those engines. In either case, solid video series...thanks for sharing this with us!
I understand your frustration with people who always have something clever to say too, you are absolutely right about it not hurting that torque wrench. No matter what a guy does to help others, there's always someone in the world (likely jealous or having personal life issues) trying to unload their hate on us 😂...all you can do is laugh at the ridiculousness of it all. Keep on keeping on Matt!
Thanks man. in all fairness- *I* would have also done a timing belt without valve adjustment too because I had absolutely no idea these cars- or ANY car of the year would need a valve adjustment until this video!!
@@SchrodingersBox I understand, but that's what makes doing this nice...we learn new things! Many blessings 🙌
Unbolt the upper motor mount and if there is one in the front. Take a ratchet strap hook it to something solid on top of the engine. Hook the other end to something solid in front of the car like a tool box, ratchet the top of the engine forward a bit, bam rear valves now accessable.
Easiest way I found to see if valves need adjusting is with the car running. Place a large piece a paper against the exhaust tip. If there is vacuum or the exhaust is pulling the paper the valves are out of adjustment. Big time saver!!
Interesting- I don’t see how that would work on an advanced exhaust timing- where would the vacuum source from?
Never ignore oil either. I put some cheap supermarket oil in turbo diesel. It dragged the turbo, car struggled to accelerate. So drained and put some better quality oil in, runs great now.
I enjoyed this video. Thanks for going back in cylinder with the pressure transducer to show the difference. I really appreciate the visual comparison. (Perhaps it is time to add a pressure transducer to my Pico kit.) I know you advocate against it, but similar to changing a timing belt every X number of miles, the valve clearances on the Honda 3.5 V6 and the the 4 cylinder should be checked once the vehicle is over 120K miles. I'm just a DIYer, and it is only anecdotal evidence, but I have checked valve clearances on two 3.5s and one 4 cylinder engine that had exceeded 120k miles and they were all out of spec. Each of these engines had valve clearance issues similar to your findings-- too tight. One of the vehicles, a Honda MDX with 160K miles, had intermittent misfires and driveability issues that a shop couldn't resolve so my buddy asked me if I could take a look at it. The valve adjustment cured the misfires and the vehicle has been running great.
I’m surprised they didn’t burn a valve after driving it this way for so long. If the valves are too tight, they hang open, and the thinner edges on the valves will get very hot and melt.
This guy is the only person on the planet that could fix this vehicle.
Hahaha thanks man. I believe others would have too though- like scannerdanner for example.
I always adjusted valves to the higher clearance for a cold engine and the lower end of a warm engine and I have been told that valve clearance will be zero backlash when 9is at operating temperatures
It is always a good idea to confirm the clearance right after you adjust it. Even when holding the threaded adjuster with a screwdriver, that final push of the locknut seems to turn the adjuster just a hair tighter. At least that's how I remember my old 1792 CB750 K, and before that, the little XR75 trail bike. P.S., a leakdown test would also have pointed you to valve clearances too tight causing leaking into the intake and or exhaust.
Yes I checked each adjustment again after two crank revolutions.
I appreciated your channel, I have been learning some important things from you
thank you for your time.
You are very welcome
Great video. I knew about valves getting looser over time, but never had heard about them getting tighter. I had to do search on that to understand why. From what I read, it is because of valve seat wear. While it was outside the scope of what you were trying to fix, it might have been educational to borescope the cylinders to see what the condition of the valves were. It is possible that a valve job is is not too far off for the car.
Agreed totally.
I just replaced the head gaskets on a single overhead cam Subaru boxer engine with 180000 miles that was very very clean inside--good oil change intervals, basically. Every valve was at minimum clearance or too tight.
God bless you. Fantastic repair, and definetly, fantastic diagnostic.
Wow thanks!!!
that is a legendary diagnosis Mr Schrodinger.
Usually valves that are adjustable is adjusted during a timing belt replacement. The key that led to valves being to tight no codes. The sensor readings especially fuel trims show rich. Tight valves keeps them slightly open when hot. Still tough to diagnose I can't understand why a fuel pump or any other sensors were replaced for nothing. I thought a leaking injector would be the cause. Great job, like to see mechanics at work.
oh man, part 2 took forever to come out I could watch this wrench turning all day
Nice job it sad Honda dealer missed that especially when it recommend that service is done during timing belt intervals as well. It is very common problem that need done on higher mileage v6 3.5. Owned a Honda 2007 Pilot and only thing needed done that ran into during own it.
I would suspect that the compression is a little higher. And surprisingly there was not pop back in the intake side. So My question is this engine had problems for years. Were they out of adjustment from the factory or a result from the valves and seats wearing in .
Amazing it ran as well as it did before. I work on a lot of small engines a UTV's such small things can cause big performance issues.
Good job
Great job! I am constantly telling others that I break mechanics down into two categories: parts changers and troubleshooters. And unfortunately, you still see a lot of parts changers even at the dealerships. I also have a saying: Does that mechanic have 10 years worth of experience, or 1 year of experience that they have held for 10 years?
Right on!
Thank you for showing this video I learned a lot. You are a good mechanic🙏
@Schrodingers Box Science is magnificent! You are an awesome detective!
Thank you kindly! Yes, science is the greatest invention in history, by far.
great thought process when reading the output from the scope, that was key to solving it
We need more people like this guy nowadays.
I wonder if vacuum gauge would have fluttered due to the valves being so tight.
hahah had this video playing in the background .. you got me hooked now bro .. hahaha part 2 !! lets do it ! i resently had a 2000 honda accord i did a valve adjustment on 4 cylinder .. glad you found the issue .. bet customers happy
where was the test drive? haha
I did one!! it drove perfectly. much better than before!
To tight valves. The valves cupped? I have seen that once on a diesel that maybe effected how it ran. Those engines were junk. Rare valve adjustment does much for noticeable engine power. They usually wear loose. Mostly a preventative maintenance thing to help prevent valve train wear. I never had a pico or pressure transducer 15 years ago to even think of that test. Love it. Good work.
200k of metal to metal beating against each other. Valve tightens up because the metal gives a little (sinking the valve), especially with the exhaust due to the high heat.
Tight valves are the silent killer...expecially exhaust valves in the first gen CRV's. Loose valves make noise, can lead to reduced power but realistically cannot cause further damage. Tight exhaust valves lead to burnt valves and in the example above, mystery idle code that is almost the only thing that (somewhat) regularly kills that particular engine even if it can be driven with that code for quite a while if you do not have mandatory emissions testing.
You are very correct!!
I worked at honda for 6 years and was one of the top guys and ive only seen this a couple of times. However with hondas rich codes are pretty rare.
Honda Fit also requires manual valve adjustments periodically. Angled feeler gauges are your friend. I found that the valves required more adjusting at the first service interval; less so on later ones.
totally agree. reason being is that during break-in there may be give or take in the cam lobes, roller rockers, valves, etc that would make the initial factory setting to become out of spec even when it was right at the first place. I have a Fit also (it's named Jazz here) and did valve adj 9,000 miles on the clock. massive difference, car runs smooth n powerful.
@@1_D333 Honda is or was, a big believer in non-hydraulic valves for a long time.
usually with a four valve engine, they recommend using two feeler gauges on both valves opened by a forked rocker arm. Just like on the four valve motorcycle engines........
Guess Honda techs 'forgot' that, most get checked every 17.5K miles. Easy to forget till you do & it runs like poo. Time for a valve clearance check.
Usually valves get loose, if they are getting tight it could very well be a sign of valve stem stretch, and things can only stretch so much before they break
Yes good observation. it’s actually due in hondas to valves recessing in the valve seat deeper over time.
As a millwright, I would use my adjustable wrench as a "light" tapper/hammer. No damage occurred to said wrench. It was a metric anyway! lol
Was at a metal working class yesterday and the horizontal bandsaw needed an angle adjustment (for the newer person in the class). Instructor goes to the board, pulls off an adjustable wrench and proceeds to explain how to use it. (new person has no shop experience). I mention something about needing to check whether it was metric or standard, and the instructor starts to look at the wrench handle. Now, either he was too smooth in admitting he fell for it, or he was looking for a smooth way out, but he mumbles something about that, and then saying it wouldn't matter a few seconds later.
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Build up of soot in exchaust valves may cause disadjustme.
Great job done dear bro
Awesome diagnostic and fix. Hats off to you sir.
Awesome mate. Keep up the good work/ posts. I'm learning heaps!
Great diagnosis with the scope and confirmed fix .
Honda K-series 4 cylinders need valve lash adjustment as well. My brother and I talked about doing it on his element, but now I'm thinking it would be worth getting an in-cylinder pressure transducer to see if that's even necessary.
I'll be going with Ivan's pressure transducer though, the pico is mighty expensive.
Bravo brother! I would love to see the owners reaction.
it drives perfect because of all the parts that were replaced before you by others. You don't deserve all the credit so don't forget to thank them. Go Scotty !
The naysayers are just looking for attention online. It does nothing to the wrench.
Tight exhaust valves actually super common on Honda J motors. Done dozens and dozens of 03-06 MDX valve adjustments for high map voltage and rich trims coupled with random misses(dealer tech). Kudos to your method of proving it with in cylinder testing though!
Great point!
The last car I adjusted valves on was an 85 300SD Mercedes 5 cylinder, over 30 yrs. ago. Excellent diagnosis!! The scientific method rules the universe, so why not your car?!!!
Well said!!!