2019-2021 engines did not appear to have near the failures of the 2022 to current. The primary difference that I have been able to find is the the 2019-2021 10 speed transmissions had the 1st generation valve body and not nearly as aggressive TCM programming. Starting in 2022 with the 2nd generation valve bodies came out with highly update TCM programming with greater Adaptive Learning and more aggressive Torque management, I really think this is where things started to go downhill.
My Non Recalled 2024 Yukon L87 Engine Is Failing - Full Of Metal @ 17k Miles
- Thread starter jfoj
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To the OP, I have read thru this thread and kept up to date with it, I would like to know where you get all your info on what GM does and Doesn't do with their engineering teams. I'm still trying to figure out where you are coming from. You have a vehicle you won't drive, insist it is a failed engine but is not part of the recall. Still not sure how you received the PICO test since it's not recalled and how the dealer got reimbursed for this work. The issue with this recall is from bad crank machining that was transferred down to Mexico as well as not properly cleaned components. I agree the PICO test and oil change is just a band aid that GM came up with quickly and we are seeing the results of that now, it will be interesting to see how the lawsuits get resolved. For the 2025 MY GM large SUV sales were over 300,000 and it's absurd to think they know the engine is bad and still keep rolling these down the line,
KMeloney
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If what you wrote here is true, then couldn't a tune be a relatively inexpensive corrective measure for GM to take?
...And would driving in Sport mode in the meantime guard against the engine lugging at high speeds/low RPMs?
“For the 2025 MY GM large SUV sales were over 300,000 and it's absurd to think they know the engine is bad and still keep rolling these down the line,“
That’s what I want to know and that’s what I think lawsuits will be based on.
That’s what I want to know and that’s what I think lawsuits will be based on.
Marky Dissod
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ahem ... beg yer pardon ...
L87 would absolutely score worse on the CAFE MpG tests if the tcm tables were rewritten to protect the engine from lugging.
Yes, but then GM would have to take the CAFE MpG tests all over again.
L87 would absolutely score worse on the CAFE MpG tests if the tcm tables were rewritten to protect the engine from lugging.
Shifting manually, or using a shift strategy that prevents the engine from less than 1625RpM whenever possible, would absolutely be wise.
LEsoftballdad
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I was driving to work today when Waze informed me of police on my route. It turns out the slowdown was caused by two police cars behind a flatbed trailer loading a beautiful red Sierra Denali. I don't know what year it was, but it had the split tailgate, and I think that was new for 2021, so it must have been within the last few years. I have no idea if it was engine-related, transmission-related, or electrical, but the woman had two small kids with her on the side of a busy road. Either way, I felt bad for her. Part of me wanted to stop and ask her what happened...
vcode
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He is speculating based on his opinion. Go back a while and he was convinced the 0W20 oil was to blame. Now it is highway engine loading based on some data he collected. Absent data on any other vehicles (like a 2019 6.2L Tahoe, or a 2021, or even a newer 5.3L), the data is essentially useless as there is nothing to compare it to. His engine may or may not fail, but as he is not driving it we will never know. And even if it does fail, without a complete teardown we will never know what actually happened. Our warranty group at work would have a field day with this.....
Marky Dissod
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If it was highway engine loading based on lugging the engine, 0w30 or 5w30 would definitely outperform 0w20 on the Stribeck curve.
For the vast majority of real world use cases from the most mundane to playing or working hard, even if 0w20 is 'acceptable', 0w30 or 5w30 is always a better option
EXCEPT in terms of trading MpGs for engine protection.
Stribeck Curve - About Tribology
Stribeck Curve: definition, concept, properties, and applications, as well as free online calculation tool available
www.tribonet.org
There is no world where I'd keep driving my vehicle if I found ANY metal shavings on the drain plug / in the oil(pan) or oil filter with no other detectable symptoms,
with the POSSIBLE exceptions of
*driving a loved one to hospital, a vaguely calculated risk (ambulances here are too rare, take too long to arrive, and not enough drivers have EVOC certification)
*driving the vehicle to the mech after confirming the replacement engine's existence in advance, again, a vaguely calculated risk
because I'd want to minimize the chances of the engine stranding me anywhere/anywhen I'd regret or fear being stranded
(Granted I say this regarding my '02 Tahoe which is old enough to rent a newer vehicle itself.)
None of the above changes the fact that GM is proximately if not directly responsible for either engine assembly/machining/prep errors,
or subcontracting some part(s) of engine assembly/machining/prep processes to those who are directly to blame.
Once an engine begins shedding visible amounts of any metal into the oil, safe bet that it's on the cusp of becoming a trans-paperweight, only question is WHEN.
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FYI up thread there is a 2024 5.3 plot from a suburban that highlights the discrepancy.
KMeloney
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Don't YOU start thinking that anyone here is telling him his truck is good-to-go for driving! lolIf it was highway engine loading based on lugging the engine, 0w30 or 5w30 would definitely outperform 0w20 on the Stribeck curve.
For the vast majority of real world use cases from the most mundane to playing or working hard, even if 0w20 is 'acceptable', 0w30 or 5w30 is always a better option
EXCEPT in terms of trading MpGs for engine protection.
There is no world where I'd keep driving my vehicle if I found ANY metal shavings on the drain plug / in the oil(pan) or oil filter with no other detectable symptoms,Stribeck Curve - About Tribology
Stribeck Curve: definition, concept, properties, and applications, as well as free online calculation tool available
with the POSSIBLE exceptions of
*driving a loved one to hospital, a vaguely calculated risk (ambulances here are too rare, take too long to arrive, and not enough drivers have EVOC certification)
*driving the vehicle to the mech after confirming the replacement engine's existence in advance, again, a vaguely calculated risk
because I'd want to minimize the chances of the engine stranding me anywhere/anywhen I'd regret or fear being stranded
(Granted I say this regarding my '02 Tahoe which is old enough to rent a newer vehicle itself.)
None of the above changes the fact that GM is proximately if not directly responsible for either engine assembly/machining/prep errors,
or subcontracting some part(s) of engine assembly/machining/prep processes to those who are directly to blame.
Once an engine begins shedding visible amounts of any metal into the oil, safe bet that it's on the cusp of becoming a trans-paperweight, only question is WHEN.
The point that I think vcode and others are making is that although the metal in the oil looks bad and likely a precursor to total engine failure, without it ever actually failing we'll never know such info like how far you can go on the engine with that level of metal in the oil, whether that really will kill the engine prematurely or not, etc. Furthermore, he doesn't factor into the global number of failed engines, potentially skewing the real numbers lower -- and that's not helpful, recourse-wise, to anyone else with the 6.2.
What I can saw with pretty good certainty is 2009-2010 with the GM bankruptcy along with the mad dash to electrify pre COVID GM lost/go rid of a lot of their ICE Powertrain staff. So a lot of institutional knowledge and experience was lost. Then understand that everyone was asked to do more with less staff, so many things did not get the attention they deserved.
I have contacts in the industry, used to work for GM and know the ins and outs of how they operate and have plenty of hands on experience. Additionally I am working through the "system" at the moment with my specific problem, my problem is not really much different from thousands of other L87 owners, many owners have had engines seize and replaced, many are just ticking time bombs waiting to seize. My problem was not supposed to happen, and I personally did a lot of things to counter any possible problems.
How GM has let this go on for so long and not come to some conclusion as what to do to correct these problems is insane. 3 internal investigations inside GM with not identifying any problem and implanting any corrective action. This just blows my mind, did they not see the problems, or did they decide to ignore them. Either what it is really bad. You would think that GM would have implemented improvements to reduce or stop the high number of failures and they would have made sure Reman engines would live a long healthy life. Maybe the Lawyers told GM not to implement changes because if they did, then they would be considered guilty for the pre-change production. But I just cannot see this as the case.
I am effectively laying down on the train tracks trying to stop the train and force the system to look at this in detail. But the Railroad is big organization and they may choose to throttle up and keep going? The people in the know may not want to see what I have to offer. At the end of the day I hope what I am doing will benefit both my case and every L87 owner, maybe it will, maybe it won't, but I have to at least try. Maybe at the end of the day, I will be left on the island by myself and the L87 community may get some resolution. I may just pull the engine out of the vehicle myself and rework it to my specs and move on, it would be the best of the evils. Replacement engine, rinse and repeat, not interested. Loose $25-$30k on the vehicle value just to get out from under it, I would rather pull the engine and sort it out myself, the vehicle value will still trash, but at least I would have a safe and reliable mode of transportation. Hell, if these things get totaled in a wreck, I wonder what insurance is paying out? If they track resale value we are all screwed. If you pay personal property tax, there is no relief based on loss of resale valve. And for anyone that is banking on any Extended Warranty to offer full coverage of a failed engines after the vehicle Powertrain Warranty has expired. Good luck I am sure every engine inspected will be flagged as an oil related failure and the Extended Warranty company will likely claim GM had a defect that they should not be responsible for. I hope I am wrong in the Extended Warranty side, but that money may not have been spent on what owners expected.
This is a very dynamic situation, while GM claims the crankshaft were the problem, what ever they did, if anything, made no change for the Post Recall engine or the Remans. The L87's are still dropping like flies. While I think the crankshaft machining and final finish may have have factored into this to a degree, this issue is really starting to look like many things are playing into what is going on. Kind of a perfect storm situation.
To back out to a 30,000 foot view of this total L87 debacle overall, at the basic and simplistic level this prolem is an oiling related problem. I do think and have the data to back everything that the way the L87 and TCM (Transmission Control Module) are tuned, and forgive me as they had combined at one point the ECU and TCM into what is considered a PCM (Powertrain Control Module) and this still may be the case, but I am focused on how the transmission programming is causing heavy Load spikes under minor grade elevation. While this Load Spiking is likely the trigger for the failures, many other things are contributing to the problem. Could/should the engine be able to survive this type of Load spiking, it should but the underlying sub systems all have to be able to support this behavior and I see a number of problem areas in the L86/L87 architecture. The L86 likely did not have level or Load spiking because it never had the 10 speed transmission from my research and the overall powertrain programming was not likely as agressive.
The problem at hand is most of the L87's in the wild likely have accelerated wear depending on how the vehicle was used and maintained, so what is the "Fix"?? This is the Billion Dollar question. We know what the first bite a the apple was, it did not work out so well. I expect the next bite may be attempting a software solution for a hardware/software related problem. Will this come to fruition?? My best guess what I know at this point is the entire L87 population that was originally Recalled, will be recalled AGAIN along with the late 2024-2026 models. I only have so many hours in the day, but I think the l87 may be in the large SUV's for 2027 while the pickups get the next generation 5.7l and 6.6l. Trust me, if I have something incorrect, someone will note my mistake and correct me quickly enough.
At the end of the day, 1,000,000 L87 owners are screwed in some way or another. If you happen to have a L87 that will run 300,000 miles without a problem great, but many won't. Resale values have tanked and likely will never recover because any recall will just barely improve the safety margin, but will not help reliability. Additionally the desirability of the L87 equipped products is really not there. What we can all be hopeful of is someone, and it will not likely be GM, finds out how to make an L87 last 300,000 miles, because with the loss of resale and desirability, even outside of Warranty, it may be wiser to throw money at the L87 if we know 100% it solves the weakness that is forcing so many of these vehicles to die on the highway.
Do I have an opinion and an I pissed, hell yea, I was hopeful this vehicle would last me 10-15+ years. It should and it could if the engine is configured correctly. Only time will tell if there is actually a reliable percentage of the L87 population, clearly the 2019-2021 appear at least on the surface to be better than 2022-date. Is there really anything different with the engine, machining, manufacturing?? We may never know.
But it seems likely oiling 101 is what is missing in these engines.
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I think powertrain/TCM tuning could help, but this is a Bandaid for the bigger problem. Prior post outlined some of the issue. While I never played with the Sport or Tow/Haul mode much and pulled any data Logs, kind of wish I had, it could help. I think the Tow/Haul mode would be better option. Unclear because I have not tested, Log or experienced if 9th and 10th gear are used at all or sparingly under lighter load conditions.
Would be interesting to see Logs with Tow/Haul Mode on a specific route with minor grade changes compared to standard Drive mode.
Again, I do expect to see some software change because it is cheaper than hardware and lots of labor hours. But this does nothing to fix any bearing damage, to just may keep the extreme loading of damaged bearings. I could be wrong.
I was willing to drive my vehicle on secondary roads less than 20 miles round trip for the Pico test, but I was not willing to drive to the selling dealer 1 hours away with 52 Interstate miles at 70 MPH each way. Could I drive around town, sure, will I take on on the 7 hour trip I made yesterday in my 2006 6.0l Vortec with 281,000 miles, hell no.If it was highway engine loading based on lugging the engine, 0w30 or 5w30 would definitely outperform 0w20 on the Stribeck curve.
For the vast majority of real world use cases from the most mundane to playing or working hard, even if 0w20 is 'acceptable', 0w30 or 5w30 is always a better option
EXCEPT in terms of trading MpGs for engine protection.
There is no world where I'd keep driving my vehicle if I found ANY metal shavings on the drain plug / in the oil(pan) or oil filter with no other detectable symptoms,Stribeck Curve - About Tribology
Stribeck Curve: definition, concept, properties, and applications, as well as free online calculation tool available
with the POSSIBLE exceptions of
*driving a loved one to hospital, a vaguely calculated risk (ambulances here are too rare, take too long to arrive, and not enough drivers have EVOC certification)
*driving the vehicle to the mech after confirming the replacement engine's existence in advance, again, a vaguely calculated risk
because I'd want to minimize the chances of the engine stranding me anywhere/anywhen I'd regret or fear being stranded
(Granted I say this regarding my '02 Tahoe which is old enough to rent a newer vehicle itself.)
None of the above changes the fact that GM is proximately if not directly responsible for either engine assembly/machining/prep errors,
or subcontracting some part(s) of engine assembly/machining/prep processes to those who are directly to blame.
Once an engine begins shedding visible amounts of any metal into the oil, safe bet that it's on the cusp of becoming a trans-paperweight, only question is WHEN.
My wife would not be very pleasant to deal with stranded 70 miles from any sizeable town that actually has a GM dealer, not to mention the HOURS waiting to be towed and trying to figure out alternate transportation.
When your wife will not ride in the vehicle because she has seen the evidence, and she knows enough to realize an engine full of metal is not reliable, what are you going to do!!
Actually at the end of the day the engine is move valuable at it is either from a core standpoint or from an investigative standpoint.
Marky Dissod
Full Access Member
With the likely exception of GM corporate, this statement is very true.
I will continue to insist that GM taking a gander inside the oilpan - or even bothering to do a UOA - instead of coming up with the PICO test
would be far more valuable as a learning tool & harbinger of what not to do next time, which seems like why GM did not want to do either of the former.
vcode
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Let's not forget he is also running a DFM delete and did major mods to his transmission, including replacing the valve body. Does this affect anything? Who knows. Would need to see a load chart on a bone stock unit to know for sure.If it was highway engine loading based on lugging the engine, 0w30 or 5w30 would definitely outperform 0w20 on the Stribeck curve.
For the vast majority of real world use cases from the most mundane to playing or working hard, even if 0w20 is 'acceptable', 0w30 or 5w30 is always a better option
EXCEPT in terms of trading MpGs for engine protection.
There is no world where I'd keep driving my vehicle if I found ANY metal shavings on the drain plug / in the oil(pan) or oil filter with no other detectable symptoms,Stribeck Curve - About Tribology
Stribeck Curve: definition, concept, properties, and applications, as well as free online calculation tool available
with the POSSIBLE exceptions of
*driving a loved one to hospital, a vaguely calculated risk (ambulances here are too rare, take too long to arrive, and not enough drivers have EVOC certification)
*driving the vehicle to the mech after confirming the replacement engine's existence in advance, again, a vaguely calculated risk
because I'd want to minimize the chances of the engine stranding me anywhere/anywhen I'd regret or fear being stranded
(Granted I say this regarding my '02 Tahoe which is old enough to rent a newer vehicle itself.)
None of the above changes the fact that GM is proximately if not directly responsible for either engine assembly/machining/prep errors,
or subcontracting some part(s) of engine assembly/machining/prep processes to those who are directly to blame.
Once an engine begins shedding visible amounts of any metal into the oil, safe bet that it's on the cusp of becoming a trans-paperweight, only question is WHEN.
All Data Logging was performed well before transmission valve body was upgraded. DFM/ASS disable has no real impact. Grades would have put engine in same loading condition.
Oil Analysis did not show downward metal trend until last sample when engine was full of metal. GM screwed up, I hope the L87 failures will com to an end soon, but this does not appear to be the case.
Even the 2 stage oil pump control is not clear, online info seem to indicate it is PWM controlled, which it may be, I never scoped the signal because all my logging showed at least high pressure was RPM based around 3200 RPM which these engines only see when accelerating into a highway ramp or passing fairly aggressively on the highway. Only other condition would possibly be while towing but I never towed with my vehicle.
No time when load spiking occured did I see oil pressure follow and increase.
Oil Analysis did not show downward metal trend until last sample when engine was full of metal. GM screwed up, I hope the L87 failures will com to an end soon, but this does not appear to be the case.
Even the 2 stage oil pump control is not clear, online info seem to indicate it is PWM controlled, which it may be, I never scoped the signal because all my logging showed at least high pressure was RPM based around 3200 RPM which these engines only see when accelerating into a highway ramp or passing fairly aggressively on the highway. Only other condition would possibly be while towing but I never towed with my vehicle.
No time when load spiking occured did I see oil pressure follow and increase.
Marky Dissod
Full Access Member
Disabling & deleting Cylinder Confusion, and replacing the valve body are both supposed to be enhancements;
unless/until proven to be otherwise that's how I'd assess them from prior experiences with other AFM/DFM engines & 8L80/10L80 transmissions.
I noticed early on with my '23 that it likes to run at 1,200 RPM in tenth gear sometimes. Usually at around 50-55 mph. I'm sure this is due to CAFE requirements. I've always just used tow/haul to mitigate this. It just never happens in tow/haul, and I really like the programming much better even if I'm not towing, or hauling. I didn't buy this thing to save gas. GM probably isn't allowed to tell us to all run in tow/haul, but I'm sure the bearing problem has a lot to do with the load-spike issues you're pointed out. I think all L87 owners should try this.
Just use tow/haul mode. Never see the tachometer drop below 1,500 RPM, and it downshifts very early.
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