In a former life I was a QA auditor for a large auto company engine manufacturing plant. One of my duties was a periodic check of the torque to yield machinery. This involved using bolts that had been measured for length, running them through the machine and checking they had stretched the specified amount to achieve the desired loading. The bolts needed to be taken to the point where the material was stretched to the extent it became "plastic". This is what you see in fasteners with threads that have "necked" just prior to breaking but on a smaller scale. That is why manufacturers specify the bolts are replaced because the crystal structure has been altered and the fastener material can't be relied on to achieve the desired loading. They may torque up but the loading will be incorrect. Cheers Eric
Yeah I cringed when he said that, and mentioned only torquing to 60 and then 80. Putting an engine together I forgot to do something and had to take out some torque-to-yield bolts. Didn't have any run time, but I just sucked it up and bought new ones.
Yup, once I unknowingly tried to reuse torque yield bolts and they would not come up to torque, they just kept stretching and I knew something was wrong. Did some research and learned they were torque yield bolts, stopped the project and ordered new bolts. Torque yield bolts should be labeled as such.
@@areuaware6842It's pretty much assumed that any engine with aluminum heads will have torque to yield head bolts. This is universal. Cast iron block and heads usually don't have torque to yield bolts.
Very impressive, Ivan. You called the shot "spot on" and executed it flawlessly in just one day! Your diagnostic techniques are like x-ray vision and I am learning so much by watching your videos. Bravo!!!
Not taking anything away from Ivan . . . there's a class action law suit for this issue so it's rather easy for a pro to know what the problem is. They knew it could happen which is why they disabled the AFM with a tune (but it did not help) Still, It's great that Ivan showed us just what the issue is with the proper tools and wave forms. At least proving it was not some other issue. Great Video. The GM warranty and class action suit does not mention this year model truck so I wonder what year this engine is. It might happen again because GM never fixed the problem unless the tune that disables the feature truly fixes it. I dont know for sure. The tune might be illegal in California.
@@hikerJohn Well, like the old saying even a broken clock is right twice a day. You can always go with a common problem but you gotta prove it even if you suspect. Ivan shows pretty solid proof. Way to much work to go down the rabbit hole without evidence. The trap for young players is confirmation bias. That's why the explanation at the beginning was really important. Just like math class, you got to show your proof, being right doesn't count if you got there the wrong way.
Good going! Being an oscilloscope user for many years, I hafta say the most impressive feature of the Pico Scope for me is the way the cursors can be set up to show degrees instead of milliseconds - and the fact that you set up only the 0 and 720 degree points with the others scaling in automatically. Being mainly a DIY'er and having a couple of regular scopes, I don't think I can justify buying a Pico Scope setup, but it's mighty tempting. Maybe I'll spring for a pressure transducer one day. The Pico Scope screen reminds me of some National Instruments data logging equipment I used on the job before retiring. I saw on the MythBusters show that they used National Instruments data logging equipment on explosions due to the very fast response time.
Ivan, the only way to truly prevent a repeat on this is to re cam the engine with the non AFM cam from GM. I did mine last summer and changed all 16 lifters with standard lifters. The AFM had to be disabled in the ECU as well as the warning lights for the AFM malfunction. The stock tune with the non dod cam is good enough that it did not have to be re road tuned. Little root cause analysis for you..... There are 2 reasons those lifters fail. 1. clogged screen under the oil sending unit... GM has a tech bulletin out on that. 2. The VLOM (valley lifter oil manifold) has oil seals for the top of each oil galley tower... they are notorious for leaking inside the engine while running which causes the lifter minimum oil pressure to be exceeded... which I think is 25 psi and that causes the pins to lock the lifter in the AFM activated mode and will not release the lifter. Whenever you do one side, do the other side and use new bolts, there is a procedure to follow for the head bolt torquing because they are torque to yield and are only supposed to be used once. If you go the AFM delete as I described with a camshaft and such, reach out to me and i will hook you up with part numbers from summit for the delete kits. the kits come with almost everything needed except head and intake gaskets. GM non dod cam: 12689035 the cam profile is almost an identical match to the AFM cam. note: DO NOT put 16 standard lifters in these engines without changing the cam or the afm cylinders will be about 25% low on compression. The dod cam has different ramp rates on the DOD lobes. Will send you an email with my details for the parts. that cam is for the 5.3 L engine FYI
Ivan, the L83 is an excellent motor. I am an original LTZ 1500, 100K miles, ZERO issues, BUT I took serious care of it. Mobil1 every 4K. Valvoline Max Life ATF, etc. The truck is flawless. I can practically guarantee that this motor was not rebuilt or tore down before the install.
Nice work Ivan! Always be careful around collapsed stuck springs. You never know when one will let loose. I was rebuilding some fluid control valves and one had a collapsed stuck spring. I removed it and tossed it on the bench, it let loose and flew across the room. I was the only one in the room and did not get hit, but it did get my attention. Just something to think about. lol
For the record, disabling AFM with a tune does not stop the lifters from failing, at all. Mine failed at 50k and again at 116k with AFM disabled. I'll be doing a proper delete next.
I've had good luck freeing these lifters when stuck with a pop from a small hammer, using a longer pushrod. But a replacement is always best of course. Nice work as usual.
what i do NOT like is disregarding the torque to yield instructions. "yield" DOES mean the material has been stretched, you're doing a potential dis-service in "getting away with " reusing them. I had nearly 20 years in the dealer auto repair environment and seeing a few do-it-yourself broken head bolts showed the reasoning. Otherwise i do appreciate the way you go about this.
I would have replaced the head bolts, especially since the owner beats on his vehicle. Also would be interested to see the collapsed lifter taken apart to see what caused the collapse.
TTY bolts physically stretch once, when they are installed. The idea is that they have a even clamping force in their yield range. For as involved as it is to pull the head, and the damage that could be done with coolant or exhaust gasses bypassing the head gasket, I certainly would have replaced the bolts. They really aren't that expensive. MANY engines have TTY head bolts nowadays, and they say to replace them for a reason. I'm all for taking little shortcuts to save time or money, but this is one nobody should be skipping.
I disabled my Fuel Management with and aftermarket chip. It prevents the computer from shutting down cylinders to go from v8 to v6 on idle. They say it helps prevent this kind of headaches. Nice repair and diagnosis.
I don't know, I think I would have invested a bit more into the "repair" and just did the complete delete of the AFM with new cam and lifters. Who knows how long it's going to be before another one of those jinxed lifters goes South, even with the AFM disabled. Then you'll be into her again.
I'll second the comment regarding replacing the torque to yield head bolts and I come from the days before the torque to yield crap. Once torque to yield bolts are stretched, supposedly, they never hold right again. But here's hoping you get lucky.
the lifters on AFM engines are different. Cylinders 1, 4, 6, and 7 have taller lifters with oil holes in them. These are the cylinders that will shut off when AFM is activated
Hi Ivan, I did the same job about 3 months ago, the "funny" part it was 2012 Sierra with the same issue, #6 cylinder intake valve lifter. The oil changes were neglected on it. Oh well, bad cars and bad maintenance put the food on our tables!👍
Modern engines just can't take extended oil intervals if the vehicle sees too many short trips or long idle time in the winter. People assume that since they bought the expensive boutique full-syn engine oil that it somehow breaks down abrasive carbon soot and unburned gasoline. Modern engines use oil for a lot of things and it has to flow enough through a lot of tiny passages whether its AFM... or DOHC engine with VVT solenoids, cam phasers, and hydraulic lash adjusters. Water, gasoline, and carbon soot will eventually lead to increased wear or clogged oil passages. Modern engines don't tolerate that kind of thing. I've seen Toyota 5.7's that had VVT issues at relatively low mileage simply because of sludge clogging up the VVT system.
Ivan, great video. Thanks for including the PICO waveforms. It looks like you were doing something different with the third and fourth one. Couldn't quite follow them. Your explanation along with the first two waveforms is excellent. This is a beautiful truck which was my impression of it when I saw it the first time with the blown engine. Sure would like to see it work out finally for your customer. Thanks for Sharing!
Short-cutting things like no oil change, no head bolts and I didn't hear you say you replaced the fuel lines that were removed. GM states they are one-time use. With the past history of the owner beating the crap out of this truck. I would of never even thought of not following the repair guidelines. Good Luck with this one. I think you may need lots of it.
You are 100% correct. I really like Ivans videos, but his cavalier attitude about clearly doing things wrong here just bugs me. These are not tips, they are essential replacements to do the job properly and avoid problems in the future. His diagnostic work is top notch, but the wrenching should be either left to the professionals, or not shown on youtube for all the world to judge. People aren't pointing it out because they are picky. It's because the repair was done incorrectly.
Nice case study. On another video of a lifter problem the mechanic also replaced the camshaft, which showed dramatic galling and erosion of the cam lobe. It would be much more work, and I don't even know if it possible with the engine in the car. I wonder how you can decide the camshaft is destroyed as well. Maybe borescope? It seems like a lot more work for a junkyard engine....
What you can do with a pico is amazing. Such a precise diagnosis. Right on target. Ivan Thanks again for the pressure sensor kit. What a good alternative to brand transducer.
@@fredwalker839 Yup. At the very least pull the drain plug and let the coolant drain out of it. 😂 Put it back in when you see oil😉 Or just change the oil🙃. That job should have gotten new head bolts, new plastic lifter guides and an oil change. 😉
Reusing Torque to yield could be a bad idea. Once steel is at yield point, next comes ultimate strength and then FAILURE. I studied strength of materials in college.
Since this vehicle gets abused I would change the head bolts along with the oil and filter. I would put in writing for the customer warranty for the new parts but there is the possibility there may be more problems with that engine and more repairs needed which are not part of the warranty for this job. Also I would have flushed out the oil pan looking for broken parts and "metal" in the pan.
I have a 17 silverado with almost a hundred thousand and had no issues but I have not over revved the engine . I believe these lifters for the fuel management are not made for high rpms
That was really good pay off when you compared the lifters side by side. Like you said the wave forms looked "normal" but comparison is key to understanding even if you don't know what you're looking for spotting the odd man out can be a good clue. Thanks for sharing Ivan. Man that was a lot of work. Phew. Hope it lasts more than 4k this time.
So I wasnt going to buy new head bolts for mine but at the last second I found a good deal on a set and ik you can totally reuse them with good results(sloppy mechanics has good content proving this) but my original bolts were clearly visibly stretched which in practice doesn't seem to matter but it certainly is a thing and an awesome cop out for manufacturers to not stand behind sub par head gaskets lol
I agree 👍. Sometimes chevy will get a awesome thing going and for some reason they completely destroye the progress or just scrap it. The worst part is the customer pays for the trial and error. It wouldn't surprise me if I heard car manufacturers get a ideal build it test it for 5 months in perfect conditions then ship it. It seems to.be the theme lately with all manufacturers across all fields. My wife bought that new Samsung flip phone and 5 months later the screen goes black at where it folds. It was a 1200 phone which is ridiculous to begin with and Samsung won't warranty it. So her phone company says its a manufacturers warranty Samsung will take care of it. Samsung is saying she's some what to blame but won't say whats the blame just a 200$ bill. So after refusing to pay 3 other phone repair shop said it was a defective part and should be covered. Eventually I just paid the 200 because it was already 2 months with out a phone.
@@willefixit Those cars ran so bad, my father worked for GM and had to test drive a couple of these cars from the dealer. Customer reported shimmy's and shakes when driving under normal loads. Found out the design was so flawed, they scrapped the idea and moved on with their lives.
Some years ago, in Australia, the General Motors Holden had a 'flagship' car called the Statesman, which had a 5.0 litre V8 engine fitted (308 cu. in.). Through some design flaw, one lobe on the camshaft and its lifter was starved of oil, which meant one cylinder was not firing like the other 7, with a very loud 'tick'. It was a big job to replace the camshaft and lifters, and direct an oil passage to the cam and lifters, but once done, the car did another 160,000 miles with no major engine problems...
That was awesome video! But juat replacing couple lifters, but i would have replaced all of them to prevent a comebacks. But you know what you're doing. Nice and smooth job! Great job! You are the man! Nice to see the pico to see the humps and see the intake of 30 psi. I like to see how you find the fault!!
Torque to yield bolts don’t have torque spec they stretch and are under spring tension and that can only happen one time… once the yield point is reached the fastener losses it’s strength rapidly… So the clamping force if used twice will be substantially less than you think, based on how tight it seems to be…
It amazes me how many commenters love to tell u what to do. All bolts stretch when u tighten them. The torque to yield specs r too tight. Replacing the fuel lines? More crap to sell parts. Let’s watch what happens with this engine. The repair will b just fine. The next failure will b something else. Maybe. Many of these trucks go two or three hundred thousand. I have one. It runs great and gets good mileage. I also have an Odyssey. So far, so good. I also reuse bolts. And I have fixed a lot of vehicles in 55 years.
Very nice job. But normaly always replace stretch head bolts, once stretched they can't be re-used. And I assume they are the stretch type as you have to tighten them by degrees not torque.
Thats the craziest thing I captured the same waveform on a ford truck about 5 days ago. It had the slight U shape on the intake stroke (in stead of a flater line). Also my capture was just a little more noticeable but not by much.
As others have stated doing things on the cheap will bite you soon enough. Why wasn't the head bolts replaced? Very stupid not to do so. An oil change was warranted as well
@@PineHollowAutoDiagnostics My response was towards the person/shop that put the bone yard engine in the truck as, in my opinion, they should've replaced all the DOD lifters then. Question, don't they make "non DOD" lifters to swap out the ones that always fail?
Great video! This would purely be upon the owner, but when going this far into an engine for a known problem; seems silly to not change the opposite side as well.... Head Studs, preferably if replacing head bolts upon performance vehicles!
These pressure wave form analysis are on a different level. Most of the mechanics around here wouldn't even know what an oscilloscope is..😕😕😕 question: the waveform differences are very subtle, Is it enough evidence to justify a teardown? Personally i would have considered perhaps an inlet vacuum reading with a transducer? I personally would like to see a little more evidence before I tear into something. Cheers Ivan 😊😊fantastic video as always.
When I replaced the hydraulic lifters in my 5.7 litre Chevrolet LS1 V8 engine 3 1/2 years ago cylinder number 6 was the worst because the exhaust valve lifter for that cylinder was jamming up in the engine block because it was mushroomed on the roller end. Apparently all of the lifters were doing it a bit in all cylinders bar cylinder number 8 because there were Valve marks where the pistons had been hitting on the valves in all cylinders except number 8,the engine has been going good ever since. Yes, you're supposed to replace the cylinder head bolts because they stretch & they're done up very tight,I replaced all of the hydraulic lifters for $100 AUD per set for aftermarket LS7 items & $66 AUD fur the aftermarket cylinder head bolts so I didn't blow the $110 AUD genuine GM cylinder head gaskets because the old cylinder head bolts didn't reach the required torque capacity because they stretched again. Mine is about to clock over to 374,000 kilometres (232,400 Miles) tomorrow & it's going good, sticking the pushrods in the box was probably my idea if the person who you found out that information from copied off me in 2018 when I did that hydraulic lifters replacement Albeit in a non AFM or DOD engine. I posted that on Facebook !
Not sure why people still buy GM AFM engines. GM found a way to turn one of their best engines into a ticking time bomb. Will the lifters make it to 3k miles? 30k miles? 80k? No manufacturer to date has come up with a reliable AFM system.
@@tokuzumi1 At lunch or coffee break? They sneak? Also I have been rebuilding engines Gas Diesel industrial marine since 1976. And I recall the soft cams in mid late 1979s GM then.. Changed countless cams lifters then.
60 and 80 might be off from foreseen torque value. I just did a head, and took a calibrated electronic torque wrench with me from work (aviation). I had to to 60nm, +90, +90. It shows the torque at the end of the degree's torque. The last ones ended at 136-143 NM... That's more then double of the initial torque. Anyhow this was on 3 cyl 1.4 TDI engine. They don't even make em that small in the states 😅
Any chance the slight decrease in vacuum was a result of fuel being injected and not the intake valve opening for 40 degrees? (Fuel vaporization in cylinder)
they can still collapse or break again due to the metal used in the crafting of the lifter. im sure you're aware of the lawsuit thats coming about the issue. the only perma fix currently is to remove it entirely then force gm to pay you back after the class action suit is done.
I've done enough of them to have dreams about them, my wife at first was confused to why I was cussing in my sleep about the horrible design of the AFM system on them engines.
Dear Mr. Ivan, Thank you always for your wonderful videos. I do not think you need to resurface the head specially if unbolted when the engine is overnight cold ? I wonder if that apply to most brands or maybe someone could make a straight edge measurements. Thank you a lot. John Kaplanian from Jordan / Middle East.
The last one I did several head bolts stripped out on the final torque, had to pull apart and repair with timeserts. Found out its more common than you would think. Way to go GM...
@@PineHollowAutoDiagnostics Everything was meticulously clean, the first bolt that stripped was on the second pass, not sure what torque , upon removing all the bolts found several that had aluminum on the threads and visually could see the threads were gone Found a company that sells a drilling jig and taps etc . Talking with the guys there he said he sells a lot of jigs and inserts . It was quite a job to get it squared away.
@@PineHollowAutoDiagnostics ruined my day once. On a 98 lumina after replacing head gaskets. Was tightening down the rocker arms and got almost done and had one pull the threads just before the torque wrench would have clicked. No fun.
Cylinders are shut down when less power is required AND I suspect this causes uneven wear and/or oil starvation to the rollers on the lifters and/or destroys the lobes on the camshaft and this is the result. Watch Scotty Kilmer and see what he thinks about AFM. Pure nonsensical GM crap.
@@mikefoehr235 It worked just fine with the Chrysler Hemis from 2005 thru 2008. Then the hemis started having lifter problems when they added variable cam timing to the hemi in 2009.
@@mikefoehr235 XD, I remember GM had the V-8-6-4 and don't remember them lasting very long. I have not seen one in years while others from 80's are still going.
when you first got the first launch scanner i bought one like you had . the updates are all used up and to get any more updates i have to pay. i am thinking about getting a new scanner can't afford a snapon at this time if i could would. which scanner do you reccomend me getting best bang for the money
@@PineHollowAutoDiagnostics is there a certain model number i should be looking at i have a auto repair shop but work by myself and am 65 years old so don't do as much work and will probably be the last scanner i buy so i would like to get the best bang for the buck. and thanks for taking the time to respond
In a former life I was a QA auditor for a large auto company engine manufacturing plant. One of my duties was a periodic check of the torque to yield machinery.
This involved using bolts that had been measured for length, running them through the machine and checking they had stretched the specified amount to achieve the desired loading.
The bolts needed to be taken to the point where the material was stretched to the extent it became "plastic". This is what you see in fasteners with threads that have "necked" just prior to breaking but on a smaller scale.
That is why manufacturers specify the bolts are replaced because the crystal structure has been altered and the fastener material can't be relied on to achieve the desired loading. They may torque up but the loading will be incorrect.
Cheers Eric
Yeah I cringed when he said that, and mentioned only torquing to 60 and then 80. Putting an engine together I forgot to do something and had to take out some torque-to-yield bolts. Didn't have any run time, but I just sucked it up and bought new ones.
Yep it's too big of a job to not use the correct bolts.
Yup, once I unknowingly tried to reuse torque yield bolts and they would not come up to torque, they just kept stretching and I knew something was wrong. Did some research and learned they were torque yield bolts, stopped the project and ordered new bolts.
Torque yield bolts should be labeled as such.
@@areuaware6842It's pretty much assumed that any engine with aluminum heads will have torque to yield head bolts. This is universal. Cast iron block and heads usually don't have torque to yield bolts.
Very impressive, Ivan. You called the shot "spot on" and executed it flawlessly in just one day! Your diagnostic techniques are like x-ray vision and I am learning so much by watching your videos. Bravo!!!
Thanks for the kind words Mike :)
Not taking anything away from Ivan . . . there's a class action law suit for this issue so it's rather easy for a pro to know what the problem is. They knew it could happen which is why they disabled the AFM with a tune (but it did not help) Still, It's great that Ivan showed us just what the issue is with the proper tools and wave forms. At least proving it was not some other issue. Great Video. The GM warranty and class action suit does not mention this year model truck so I wonder what year this engine is. It might happen again because GM never fixed the problem unless the tune that disables the feature truly fixes it. I dont know for sure. The tune might be illegal in California.
@@hikerJohn Well, like the old saying even a broken clock is right twice a day. You can always go with a common problem but you gotta prove it even if you suspect. Ivan shows pretty solid proof. Way to much work to go down the rabbit hole without evidence. The trap for young players is confirmation bias. That's why the explanation at the beginning was really important. Just like math class, you got to show your proof, being right doesn't count if you got there the wrong way.
Mikey, he sure did after his friend Al screwed up
@@111-c7x2t I don’t get how his friend screwed up !
Good going! Being an oscilloscope user for many years, I hafta say the most impressive feature of the Pico Scope for me is the way the cursors can be set up to show degrees instead of milliseconds - and the fact that you set up only the 0 and 720 degree points with the others scaling in automatically. Being mainly a DIY'er and having a couple of regular scopes, I don't think I can justify buying a Pico Scope setup, but it's mighty tempting. Maybe I'll spring for a pressure transducer one day. The Pico Scope screen reminds me of some National Instruments data logging equipment I used on the job before retiring. I saw on the MythBusters show that they used National Instruments data logging equipment on explosions due to the very fast response time.
Ivan, the only way to truly prevent a repeat on this is to re cam the engine with the non AFM cam from GM. I did mine last summer and changed all 16 lifters with standard lifters. The AFM had to be disabled in the ECU as well as the warning lights for the AFM malfunction. The stock tune with the non dod cam is good enough that it did not have to be re road tuned. Little root cause analysis for you..... There are 2 reasons those lifters fail. 1. clogged screen under the oil sending unit... GM has a tech bulletin out on that. 2. The VLOM (valley lifter oil manifold) has oil seals for the top of each oil galley tower... they are notorious for leaking inside the engine while running which causes the lifter minimum oil pressure to be exceeded... which I think is 25 psi and that causes the pins to lock the lifter in the AFM activated mode and will not release the lifter. Whenever you do one side, do the other side and use new bolts, there is a procedure to follow for the head bolt torquing because they are torque to yield and are only supposed to be used once. If you go the AFM delete as I described with a camshaft and such, reach out to me and i will hook you up with part numbers from summit for the delete kits. the kits come with almost everything needed except head and intake gaskets. GM non dod cam: 12689035 the cam profile is almost an identical match to the AFM cam. note: DO NOT put 16 standard lifters in these engines without changing the cam or the afm cylinders will be about 25% low on compression. The dod cam has different ramp rates on the DOD lobes. Will send you an email with my details for the parts. that cam is for the 5.3 L engine FYI
I disagree. I have over 500K on AFM/DFM engines. No failures. I can't tell you what I'm doing differently but it's working.
@@davidporter7051 what year?
Sounds like you been through it on these engines. All great advice and awesome info. Thanks for enlightening us!
@@davidporter7051 Is it a Chinese secret? 😁😁😁😁😁
07 and 18.
These videos are amazing. Ivan thinks the problem through...and his ability to focus all his energy on the solution is uncanny. Great video!
Ivan, the L83 is an excellent motor. I am an original LTZ 1500, 100K miles, ZERO issues, BUT I took serious care of it. Mobil1 every 4K. Valvoline Max Life ATF, etc. The truck is flawless. I can practically guarantee that this motor was not rebuilt or tore down before the install.
I'm liking the Pico scope! Definitely a must in this day and age.
Nice work Ivan! Always be careful around collapsed stuck springs. You never know when one will let loose. I was rebuilding some fluid control valves and one had a collapsed stuck spring. I removed it and tossed it on the bench, it let loose and flew across the room. I was the only one in the room and did not get hit, but it did get my attention. Just something to think about. lol
Great to see “the science” behind a lifter tick diagnosis. Well done as always.
The head bolts stretch that's why they want you to use new ones
For the record, disabling AFM with a tune does not stop the lifters from failing, at all. Mine failed at 50k and again at 116k with AFM disabled. I'll be doing a proper delete next.
I've had good luck freeing these lifters when stuck with a pop from a small hammer, using a longer pushrod. But a replacement is always best of course.
Nice work as usual.
And what would prevent it from getting stuck again? Keep in mind that it was ticking for a while before it broke completely 😆
what i do NOT like is disregarding the torque to yield instructions. "yield" DOES mean the material has been stretched, you're doing a potential dis-service in "getting away with " reusing them. I had nearly 20 years in the dealer auto repair environment and seeing a few do-it-yourself broken head bolts showed the reasoning. Otherwise i do appreciate the way you go about this.
I would have replaced the head bolts, especially since the owner beats on his vehicle. Also would be interested to see the collapsed lifter taken apart to see what caused the collapse.
TTY bolts physically stretch once, when they are installed. The idea is that they have a even clamping force in their yield range. For as involved as it is to pull the head, and the damage that could be done with coolant or exhaust gasses bypassing the head gasket, I certainly would have replaced the bolts. They really aren't that expensive. MANY engines have TTY head bolts nowadays, and they say to replace them for a reason. I'm all for taking little shortcuts to save time or money, but this is one nobody should be skipping.
Absolutley. This thing is a bomb waiting to go off now.
@@Bobbywolf64 I would agree but since Ivan didn't I think since he only torqued them to 80 ft. lbs., I'd retorque them before too long.
@@billmonroe8826 it’s also 60 lb/ft then 90 degree turn, then 60 degree turn.
So TTY is based on different specs than “oh tighten to XX lb/ft.”
I don't know why they sell head gaskets without the bolts.
I disabled my Fuel Management with and aftermarket chip. It prevents the computer from shutting down cylinders to go from v8 to v6 on idle. They say it helps prevent this kind of headaches. Nice repair and diagnosis.
843 videos and I've watched all...
Long time wasn't around Ivan. My best entertainment buddy
Wow that's a lot of videos! 😁👌
@@PineHollowAutoDiagnostics ask me, it's never enough for me 😬🤣
I don't know, I think I would have invested a bit more into the "repair" and just did the complete delete of the AFM with new cam and lifters. Who knows how long it's going to be before another one of those jinxed lifters goes South, even with the AFM disabled. Then you'll be into her again.
$$$$$$$ ? Must be ! Won’t last…. Any bets ? 10 to 1 Boom,,,,,2 months tops ! LOL,,, not funny really !
The owner of that lifter factory is a happy man.
I'll second the comment regarding replacing the torque to yield head bolts and I come from the days before the torque to yield crap. Once torque to yield bolts are stretched, supposedly, they never hold right again. But here's hoping you get lucky.
Ivan was cheezing when that chevy started nicely. Great man doing his job, feeling happy at the end of the day!
the lifters on AFM engines are different. Cylinders 1, 4, 6, and 7 have taller lifters with oil holes in them. These are the cylinders that will shut off when AFM is activated
That's really interesting. I would have thought it was all electronic.
@@billsmith5166 kinda, computer sends a signal to open or close a solenoid which allows oil pressure to expand the lifter.
@@billsmith5166 The electronics controlling the lifters can fail, too. GM!! 😁
Hi Ivan, I did the same job about 3 months ago, the "funny" part it was 2012 Sierra with the same issue, #6 cylinder intake valve lifter. The oil changes were neglected on it. Oh well, bad cars and bad maintenance put the food on our tables!👍
Modern engines just can't take extended oil intervals if the vehicle sees too many short trips or long idle time in the winter. People assume that since they bought the expensive boutique full-syn engine oil that it somehow breaks down abrasive carbon soot and unburned gasoline. Modern engines use oil for a lot of things and it has to flow enough through a lot of tiny passages whether its AFM... or DOHC engine with VVT solenoids, cam phasers, and hydraulic lash adjusters. Water, gasoline, and carbon soot will eventually lead to increased wear or clogged oil passages. Modern engines don't tolerate that kind of thing. I've seen Toyota 5.7's that had VVT issues at relatively low mileage simply because of sludge clogging up the VVT system.
You're always taking a chance with junk yard mills. For better reliability, change out lifters, water pump, oil pump and seals.
Ivan, great video. Thanks for including the PICO waveforms. It looks like you were doing something different with the third and fourth one. Couldn't quite follow them. Your explanation along with the first two waveforms is excellent. This is a beautiful truck which was my impression of it when I saw it the first time with the blown engine. Sure would like to see it work out finally for your customer. Thanks for Sharing!
Short-cutting things like no oil change, no head bolts and I didn't hear you say you replaced the fuel lines that were removed. GM states they are one-time use. With the past history of the owner beating the crap out of this truck. I would of never even thought of not following the repair guidelines. Good Luck with this one. I think you may need lots of it.
Right. If those fuel lines leak slightly it might not be noticeable until the thing catches on fire somewhere.
Thanks for the tips
@@PineHollowAutoDiagnostics He said, knowing that it's going to be completely fine 😂
@@firstlast--- The Egg timer “is “ tickin !
You are 100% correct. I really like Ivans videos, but his cavalier attitude about clearly doing things wrong here just bugs me. These are not tips, they are essential replacements to do the job properly and avoid problems in the future. His diagnostic work is top notch, but the wrenching should be either left to the professionals, or not shown on youtube for all the world to judge. People aren't pointing it out because they are picky. It's because the repair was done incorrectly.
Nice case study. On another video of a lifter problem the mechanic also replaced the camshaft, which showed dramatic galling and erosion of the cam lobe. It would be much more work, and I don't even know if it possible with the engine in the car. I wonder how you can decide the camshaft is destroyed as well. Maybe borescope? It seems like a lot more work for a junkyard engine....
Good diag and repair Ivan , as you say a lot of work and Labour for a seemingly shoddy part 😮.
What you can do with a pico is amazing. Such a precise diagnosis. Right on target. Ivan
Thanks again for the pressure sensor kit. What a good alternative to brand transducer.
Brilliant work, shouldn’t you change the oil because of water getting into engine when taking the head off?
No water got into the engine... Oil ports are above the cylinders and I obviously wiped up the coolant that got in the cylinder 😁
Penny wise,,,, dollar foolish ! After all that,,,what’s an oil change ?
@@fredwalker839 Yup. At the very least pull the drain plug and let the coolant drain out of it. 😂 Put it back in when you see oil😉 Or just change the oil🙃. That job should have gotten new head bolts, new plastic lifter guides and an oil change. 😉
Head bolts stretchy, always replace with new ones. Ford, GM, Dodge all state that. I know the after market ARP bolts state they can be reused.
Dodge service info does not state to replace head bolts in the HEMI. I reuse them after checking/cleaning them.
Reusing Torque to yield could be a bad idea. Once steel is at yield point, next comes ultimate strength and then FAILURE. I studied strength of materials in college.
Wow! You have to remove the head in order to replace the lifter? What a great design G.M.!!!
Since this vehicle gets abused I would change the head bolts along with the oil and filter. I would put in writing for the customer warranty for the new parts but there is the possibility there may be more problems with that engine and more repairs needed which are not part of the warranty for this job. Also I would have flushed out the oil pan looking for broken parts and "metal" in the pan.
You didn't change the oil with coolant in the cylinders? Why not?
Ivan: very impressed! I didn’t think you would have actually done the repair ! 👍👍👍👍You can only warranty the 4 lifters you replaced ! Great repair!
Nice job Ivan , great diagnosis. As Eric O.would say , Chevy thunder !
I have a 17 silverado with almost a hundred thousand and had no issues but I have not over revved the engine . I believe these lifters for the fuel management are not made for high rpms
I have a recommendation to the "kid" that owns this truck. Drive it stock. Drive it like you need it everyday for the next 15 years.
Like I said earlier,,,, you can’t fix stupid ! LOL
Yeah no kidding. I cant believe I used to hot rod around like that and then wonder why my truck was always having major issues.
I have the 2009 4.8 that doesn't have fuel management. Never had a problem with the engine yet.
That was really good pay off when you compared the lifters side by side. Like you said the wave forms looked "normal" but comparison is key to understanding even if you don't know what you're looking for spotting the odd man out can be a good clue. Thanks for sharing Ivan.
Man that was a lot of work. Phew. Hope it lasts more than 4k this time.
1
0 to 70 its a beast nice going ivan
So I wasnt going to buy new head bolts for mine but at the last second I found a good deal on a set and ik you can totally reuse them with good results(sloppy mechanics has good content proving this) but my original bolts were clearly visibly stretched which in practice doesn't seem to matter but it certainly is a thing and an awesome cop out for manufacturers to not stand behind sub par head gaskets lol
thank you for thoroughly explaining how valve function look using waveform, excellent job my man 😎👍🏾
Wow. Half-ton truck with regular cab and short box. Not to mention its V8. Was it 4WD ? Man this truck is european men dream ❤️ Nice repair also👍
Definitely use new head bolts.
The second I heard "Active Fuel Management" all I could think was "that poor owner, omg." The 5.3 is a good engine, why did GM have to ruin it?
Leave it to EPA and engineers to wreck a great engine.
I agree 👍. Sometimes chevy will get a awesome thing going and for some reason they completely destroye the progress or just scrap it. The worst part is the customer pays for the trial and error. It wouldn't surprise me if I heard car manufacturers get a ideal build it test it for 5 months in perfect conditions then ship it. It seems to.be the theme lately with all manufacturers across all fields. My wife bought that new Samsung flip phone and 5 months later the screen goes black at where it folds. It was a 1200 phone which is ridiculous to begin with and Samsung won't warranty it. So her phone company says its a manufacturers warranty Samsung will take care of it. Samsung is saying she's some what to blame but won't say whats the blame just a 200$ bill. So after refusing to pay 3 other phone repair shop said it was a defective part and should be covered. Eventually I just paid the 200 because it was already 2 months with out a phone.
468 cady dad had was 81 deleated that feature
first gen fuel mangment
was 4 ..6.. 8..
i mad e it 8 all the time same gas milage
@@willefixit Those cars ran so bad, my father worked for GM and had to test drive a couple of these cars from the dealer. Customer reported shimmy's and shakes when driving under normal loads. Found out the design was so flawed, they scrapped the idea and moved on with their lives.
Качественно проделанная работа. Приятно наблюдать за специалистом. Единственное по краям блока немного добавляют герметика.
Some years ago, in Australia, the General Motors Holden had a 'flagship' car called the Statesman, which had a 5.0 litre V8 engine fitted (308 cu. in.). Through some design flaw, one lobe on the camshaft and its lifter was starved of oil, which meant one cylinder was not firing like the other 7, with a very loud 'tick'. It was a big job to replace the camshaft and lifters, and direct an oil passage to the cam and lifters, but once done, the car did another 160,000 miles with no major engine problems...
What’s that tell ya! Soft cams from GM ‘s original supplier for sure !
@@fredwalker839 Yeah.. .. and that 'some years ago' was 35. The new camshaft was a 'Crane' cam, for economy...
Ivan shares a video, I like then watch ... it is always interesting.
Thanks Ivan.
It isn't efficient unless it's reliable. Great upload Ivan!
would recomend some oil on the rollers,lifter presoak?
This is why I keep my two 98 Chevy trucks. No AFM.
Excellent job Ivan, you know for sure how to diagnose properly, it makes the repair process go a long way and quickly
Fun fix and informative video! The classic cardboard box organizer trick handed down from some old tech I worked with.
That was awesome video! But juat replacing couple lifters, but i would have replaced all of them to prevent a comebacks. But you know what you're doing. Nice and smooth job! Great job! You are the man! Nice to see the pico to see the humps and see the intake of 30 psi. I like to see how you find the fault!!
Torque to yield bolts don’t have torque spec they stretch and are under spring tension and that can only happen one time… once the yield point is reached the fastener losses it’s strength rapidly… So the clamping force if used twice will be substantially less than you think, based on how tight it seems to be…
It amazes me how many commenters love to tell u what to do. All bolts stretch when u tighten them. The torque to yield specs r too tight. Replacing the fuel lines? More crap to sell parts. Let’s watch what happens with this engine. The repair will b just fine. The next failure will b something else. Maybe. Many of these trucks go two or three hundred thousand. I have one. It runs great and gets good mileage. I also have an Odyssey. So far, so good. I also reuse bolts. And I have fixed a lot of vehicles in 55 years.
Haha thanks Bill! Yeah truck is running fantastic after repairs. Owner is very pleased :)
I'll bet that little bump near BDC is the intake valve opening just a touch due to the strong vacuum
You should always get new head bolts and make sure your oil pressure is good I only do a relative test to check them I do a lot of these engines
Very nice job. But normaly always replace stretch head bolts, once stretched they can't be re-used. And I assume they are the stretch type as you have to tighten them by degrees not torque.
Thats the craziest thing I captured the same waveform on a ford truck about 5 days ago. It had the slight U shape on the intake stroke (in stead of a flater line). Also my capture was just a little more noticeable but not by much.
As others have stated doing things on the cheap will bite you soon enough. Why wasn't the head bolts replaced? Very stupid not to do so. An oil change was warranted as well
Couldn't imagine not putting all new lifters in the replacement engine while it's sitting on the ground but then again repair philosophies differ.
I replaced the 4 AFM lifters on this bank 👍
@@PineHollowAutoDiagnostics My response was towards the person/shop that put the bone yard engine in the truck as, in my opinion, they should've replaced all the DOD lifters then.
Question, don't they make "non DOD" lifters to swap out the ones that always fail?
If there's coolant in the cylinder why not change oil??
Because the coolant didn't get into the oil lol...and it was changed recently
@@PineHollowAutoDiagnostics you da man
Wow that was clean junkyard engine how many miles ? Love you scope work keep it coming
Nice diagnosis and great aferd perfect fix 👌
Great video! This would purely be upon the owner, but when going this far into an engine for a known problem; seems silly to not change the opposite side as well.... Head Studs, preferably if replacing head bolts upon performance vehicles!
GM love them , without GM i wouldn't have any wages.
Great Video Sir ! Looking at the odometer, 64k on the truck? On it's 2nd engine ? 😏
The first was ruined due to neglect
These pressure wave form analysis are on a different level. Most of the mechanics around here wouldn't even know what an oscilloscope is..😕😕😕
question: the waveform differences are very subtle, Is it enough evidence to justify a teardown? Personally i would have considered perhaps an inlet vacuum reading with a transducer? I personally would like to see a little more evidence before I tear into something. Cheers Ivan 😊😊fantastic video as always.
The 70psi difference in peak pressure and loud clacking was pretty substantial evidence don't you think? 😅
I had a 2014 Sierra with the v6. Hated it. Traded it.
Just wondering why you didn't try to prime those lifters by soaking them in oil first?
Would it be possible to have a transducer detect vacuum on the intake stroke?
Did you consider borescope inspect of the cam lobes?
I did that off camera, it was mint
Active fuel management, Ruh roh. Nice call and fix Ivan. GM screwed the pooch with this "reliable" system.
When I replaced the hydraulic lifters in my 5.7 litre Chevrolet LS1 V8 engine 3 1/2 years ago cylinder number 6 was the worst because the exhaust valve lifter for that cylinder was jamming up in the engine block because it was mushroomed on the roller end.
Apparently all of the lifters were doing it a bit in all cylinders bar cylinder number 8 because there were Valve marks where the pistons had been hitting on the valves in all cylinders except number 8,the engine has been going good ever since.
Yes, you're supposed to replace the cylinder head bolts because they stretch & they're done up very tight,I replaced all of the hydraulic lifters for $100 AUD per set for aftermarket LS7 items & $66 AUD fur the aftermarket cylinder head bolts so I didn't blow the $110 AUD genuine GM cylinder head gaskets because the old cylinder head bolts didn't reach the required torque capacity because they stretched again.
Mine is about to clock over to 374,000 kilometres (232,400 Miles) tomorrow & it's going good, sticking the pushrods in the box was probably my idea if the person who you found out that information from copied off me in 2018 when I did that hydraulic lifters replacement Albeit in a non AFM or DOD engine.
I posted that on Facebook !
Not sure why people still buy GM AFM engines. GM found a way to turn one of their best engines into a ticking time bomb. Will the lifters make it to 3k miles? 30k miles? 80k? No manufacturer to date has come up with a reliable AFM system.
We have two 187 k and 120k no issues good mpg also.
@@Nudnik1 Some will sneak out of the factory with components that will last. Consider yourself lucky.
@@tokuzumi1 Actually I know several others with GM no issues.
I change oil 3000 miles .
I had my older 2005 5.3 went 400k Miles still running in NYC.
@@tokuzumi1 At lunch or coffee break? They sneak?
Also I have been rebuilding engines Gas Diesel industrial marine since 1976.
And I recall the soft cams in mid late 1979s GM then..
Changed countless cams lifters then.
Ivan,
Great video, diagnosis, and fix - thank you!
Paul (in MA)
Great job, that thing has some get up and go for a big truck!
Can't believe after going to all that trouble didn't change all lifters.
Thanks Ivan great video thanks for sharing invaluable knowledge !! simple fix but the wave forms were priceless !!
60 and 80 might be off from foreseen torque value. I just did a head, and took a calibrated electronic torque wrench with me from work (aviation). I had to to 60nm, +90, +90.
It shows the torque at the end of the degree's torque. The last ones ended at 136-143 NM... That's more then double of the initial torque. Anyhow this was on 3 cyl 1.4 TDI engine. They don't even make em that small in the states 😅
Does the cam still have a lobe on it?
Yeah it was fine 👍
The new name is APM, active parts management.
Any chance the slight decrease in vacuum was a result of fuel being injected and not the intake valve opening for 40 degrees? (Fuel vaporization in cylinder)
No, since fuel is injected on the compression stroke on a direct injection engine 🙂
@@PineHollowAutoDiagnosticsHummmm... Well..... upon further reflection, I do believe I stand corrected.
Get that great GM feeling........
I would replace all the lifters on that side anyway. The cost to replace 8 is less than the cost to open the engine again.
We have the same issues on our 2021 and 2022 Tahoe PPV’s. GM still hasn’t learned from these same problems.
I learned the hard way about using old head bolts. One let go and head gasket gone. Head bolts are cheap
9:48 - but surely you'd need to check with a feeler gauge to be certain... 😉
You know, I'm something of a feeler gauge myself
I think his guess at 1/2" was pretty close.
Don't think you be able to obtain a feeler that thick.!
No damage to the cam?
they can still collapse or break again due to the metal used in the crafting of the lifter. im sure you're aware of the lawsuit thats coming about the issue. the only perma fix currently is to remove it entirely then force gm to pay you back after the class action suit is done.
Do the AFM disablers help at all if installed early?
I've done enough of them to have dreams about them, my wife at first was confused to why I was cussing in my sleep about the horrible design of the AFM system on them engines.
WOW, what skills!
You don’t have pre soak the lifters?
Dear Mr. Ivan, Thank you always for your wonderful videos. I do not think you need to resurface the head specially if unbolted when the engine is overnight cold ? I wonder if that apply to most brands or maybe someone could make a straight edge measurements. Thank you a lot. John Kaplanian from Jordan / Middle East.
The last one I did several head bolts stripped out on the final torque, had to pull apart and repair with timeserts.
Found out its more common than you would think.
Way to go GM...
Wow that sucks. What was the Torque value when they stripped? Were the bolt holes clean?
@@PineHollowAutoDiagnostics
Everything was meticulously clean, the first bolt that stripped was on the second pass, not sure what torque , upon removing all the bolts found several that had aluminum on the threads and visually could see the threads were gone
Found a company that sells a drilling jig and taps etc .
Talking with the guys there he said he sells a lot of jigs and inserts .
It was quite a job to get it squared away.
@@keltecshooter I bet that ruined your day seeing Aluminum on the threads!
@@PineHollowAutoDiagnostics ruined my day once. On a 98 lumina after replacing head gaskets. Was tightening down the rocker arms and got almost done and had one pull the threads just before the torque wrench would have clicked. No fun.
@@williegillie5712 when I worked for GM years ago that was quite an issue on all the Chevy V6 engines.
Does the AFM system work well when new Ivan?
I'm not familiar with that active fuel management it destroys the engine somehow?
Cylinders are shut down when less power is required AND I suspect this causes uneven wear and/or oil starvation to the rollers on the lifters and/or destroys the lobes on the camshaft and this is the result. Watch Scotty Kilmer and see what he thinks about AFM. Pure nonsensical GM crap.
@@mikefoehr235 It worked just fine with the Chrysler Hemis from 2005 thru 2008. Then the hemis started having lifter problems when they added variable cam timing to the hemi in 2009.
@@mikefoehr235 XD, I remember GM had the V-8-6-4 and don't remember them lasting very long. I have not seen one in years while others from 80's are still going.
@@harrylister804 GM has tried many crazy things that don't work well over the long term.
when you first got the first launch scanner i bought one like you had . the updates are all used up and to get any more updates i have to pay. i am thinking about getting a new scanner can't afford a snapon at this time if i could would. which scanner do you reccomend me getting best bang for the money
ThinkTool Pros for a shop setting hands down 👍
@@PineHollowAutoDiagnostics is there a certain model number i should be looking at i have a auto repair shop but work by myself and am 65 years old so don't do as much work and will probably be the last scanner i buy so i would like to get the best bang for the buck. and thanks for taking the time to respond