New bulletin/Campaign 6.2 L87

[KARNUT]

1 hour ago, newdude said:

 

 

So the last new GM you actually purchased was/is your 2002 Avalanche, if I am reading that correctly?  There's another user on here who's name escapes me but similar deal.  Last truck they got was an 07 or 08, had problems with it and then just hangs out here for years crapping on trucks and then always referencing their now going on 20 year old GMT-900. 

 

Can only beat the same drum for so long...  

 

Appaled at GM?  More like almost every automaker over the last 5 years.  Ford had 40 recalls JUST FOR 2025 so far.  Toyota had the bad 3.4 TT V6s in the Tundras.  COVID, chip shortages, the feds paying people for not working during that time, its a whole mass rolling snowball here.  Its all gone to $hit.  

 

I'll leave it at that and hopefully this thread sticks back to the topic here and not the past.    

2002 avalanche doesn’t have cylinder deactivation. It’s my second avalanche. I had an 01,04,06 Chevy and GMC. The last was a Tralblazer SS. Then I went Ram for awhile. At the same time I was playing with a retro ride 65 GMC with a 93 5.7 and transmission out of a suburban. With the computer transplanted to it. Later a 2 door Tahoe and my 92 modified Chevy with a 2-4 lowering beltec spring kit. 383 stroker with a whipple. My retirement truck I bought in 2014 a fully loaded Texas Edition GMC tuned to run at max HP with E-85. Turned off the cylinder deactivation and top limiter. Ran with 50 percent TM and bumped the shift point to 5900 RPM. Lost confidence with adding a whipple after reading here about lifter failure. Sold it before the warranty ran out. Stayed with my hot 92 later after 12 years of flawless performance sold it. Bought the 2002 avalanche 5 years ago. That’s just a small portion of GMs I’ve owned and modified over my 69 years. My first new big three was a 74 barracuda after the RX3 in 73. So now we’re clear we can go back. I may add I don’t have any confidence in the other brands you mentioned. Won’t likely buy those either. I rather drive the avalanche around town and the Ridgeline on trips. I have confidence in those.

Edited April 29, 2025 by KARNUT

[MrLeadFoot]

51 minutes ago, Z45 said:

Possibly because they are no longer covered by any powertrain warranty. 

That's not a good reason, as some of them still are, since they come with 5/60k powertrain, don't they? It might be because they don't have the issue.

Edited April 29, 2025 by MrLeadFoot

[MrLeadFoot]

3 hours ago, newdude said:

 

 

I think its a multi pronged approach.  The 877k engines, that was 2019-2024.  2019-2020 are not involved with this, so its more like 721k engines 2021-2024., with 598k of those being for the US market.

 

GM Recalls 721K Trucks, Full-Size SUVs Due to Defective 6.2L V-8s

 

"This story has been updated to correctly state that the approximate number of total GM vehicles from the 2021 to 2024 model years that are involved in the recall is 721,000, of which about 598K are U.S. models."

 

 

So my thought is if the engine is a good one, replace the oil to 0w40 to fortify it somehow(?).  If a truck comes in with a P0016 crank/cam correlation, it gets an engine as they are using that as a sign that the bottom end is locking up.  And then if a truck has the new oil spec in it and it still happens, it gets an engine. 

 

So it sounds like they are doing a bit of damage control here to not have to shotgun 721,000 engines into these trucks, rather replace them as needed and hopefully that allows them to keep the quality up on replacement engines.  I say this as we have a 2022.5 in right now that is getting its 3rd new engine.  The original engine failed at 12,096 in April 2023, that replacement engine has now failed at 48,188mi on the truck. 

 

So engine 2 went 36,092mi before it packed up.  Which means any replacement engines from 2021-May 30th 2024 are suspect as well.  Complaint on the repair order was "Customer states vehicle shut off while driving, will not start or crank."

 

  

I just thought of something, because I am slow like that. If there was an issue with crank alignment sitting in the case journals or rod bores are too small, wouldn't those cause a problem pretty darned soon, and once you pass a few thousand miles, you are likely one of those that do NOT have the problem specified in this particular recall? Re: the vehicle you mentioned above, were those motors relative to this specific issue, or could they have been for other reasons? To be clear, I am NOT insinuating in any way that you are wrong about anything, just asking for clarity

[newdude]

6 minutes ago, MrLeadFoot said:

I just thought of something, because I am slow like that. If there was an issue with crank alignment sitting in the case journals or rod bores are too small, wouldn't those cause a problem pretty darned soon, and once you pass a few thousand miles, you are likely one of those that do NOT have the problem specified in this particular recall? Re: the vehicle you mentioned above, were those motors relative to this specific issue, or could they have been for other reasons? To be clear, I am NOT insinuating in any way that you are wrong about anything, just asking for clarity

 

 

It "should" be a rather early on failure, yes.  Some of these reported out there so far have either failed within 1000mi or almost right off the car hauler, others have gone 10-20 thousand miles. 

[MrLeadFoot]

24 minutes ago, newdude said:

 

 

It "should" be a rather early on failure, yes.  Some of these reported out there so far have either failed within 1000mi or almost right off the car hauler, others have gone 10-20 thousand miles. 

Years ago, I rebuilt a motorcycle engine 3 times. Each time, on the test drive, an overhead cam siezed within a few minutes. Couldn't figure it out at first, and on the fourth rebuild a TINY particle finally shot out of an oil port when cleaning with air compressor nozzle. So, I would think a bad crank journal or rod bore would cause a seizure pretty darned quickly. So, maybe those of us with a few thousand miles on our 6.2s already have hope that our motors are fine, and them upping to 40w oil is just a precaution.

 

In fact, from the beginning I was always astounded that these motors ran a 20 weight oil. That seems awfully thin. Especially now that I know the Vettes run 40w. Even my C5 with meager 5.7 liter runs 30 weight. Maybe running 20 weight oil in the 6.2 trucks is what they had to do to be able to eek some MPGs out of these things and meet CAFE standards, not to mention make them bearable with their miniscule gas tanks for such a beast of an engine. No doubt, our MPGs will drop now, probably significantly over a yearly basis. I already find myself looking at my mile range every time I pass a gas station! Maybe it's their way of training us to be EV drivers. 

Edited April 29, 2025 by MrLeadFoot

[Snow White]

GM’s V8 Engine Problem Is So Bad It’s Wrecking Thousands Of Trucks And SUVs | Carscoops

According to the National Highway Traffic Safety Administration, the connecting rods and/or crankshaft could be problematic. These components were made by American Axle & Manufacturing as well as Questum Macimex, and the government agency says the problems are due to “supplier manufacturing and quality issues.”

 

Oh look, i was right lmao, sorry i couldn't resist.  AAM is Metaldyne fyi.

Of note, JP Norman was the tier 1 until 2021 i believe and went chapter 7 as previously mentioned because they lost GM as a client due to........... Metaldyne who is now part of ..... American Axle (LOL).  guess who also supplies the transmission valve bodies....... AAM happened in 94' when Final Drive and Forge Business Unit were sold off from GM, ala Harrison Radiator-Delphi, well not exactly the same but Harrison was GM for a while, I think Delphi was on again off again but i digress, but you get the gist.

 

separately

 

All Gen III and early Gen IV bearings .630˝ wide.

Late Gen IV cam bearings .775˝ wide found with a Cam Phaser (VVT) on the front of the camshaft, and high performance applications. people were replacing the 630's with 775's in 2.348˝ blocks because the 630 engines earned a reputation for spinning cam bearings. 

 

Edited April 29, 2025 by Snow White
typos

[newdude]

5 hours ago, MrLeadFoot said:

 

Thank you for the response. Am I wasting my time putting a code scanner on my truck myself, if no SES light is on? 

 

 

Pretty much.  Unless you wanted to check for any pending codes.  

 

 

3 hours ago, Snow White said:

GM’s V8 Engine Problem Is So Bad It’s Wrecking Thousands Of Trucks And SUVs | Carscoops

According to the National Highway Traffic Safety Administration, the connecting rods and/or crankshaft could be problematic. These components were made by American Axle & Manufacturing as well as Questum Macimex, and the government agency says the problems are due to “supplier manufacturing and quality issues.”

 

Oh look, i was right lmao, sorry i couldn't resist.  AAM is Metaldyne fyi.

Of note, JP Norman was the tier 1 until 2021 i believe and went chapter 7 as previously mentioned because they lost GM as a client due to........... Metaldyne who is now part of ..... American Axle (LOL).  guess who also supplies the transmission valve bodies....... AAM happened in 94' when Final Drive and Forge Business Unit were sold off from GM, ala Harrison Radiator-Delphi, well not exactly the same but Harrison was GM for a while, I think Delphi was on again off again but i digress, but you get the gist.

 

separately

 

All Gen III and early Gen IV bearings .630˝ wide.

Late Gen IV cam bearings .775˝ wide found with a Cam Phaser (VVT) on the front of the camshaft, and high performance applications. people were replacing the 630's with 775's in 2.348˝ blocks because the 630 engines earned a reputation for spinning cam bearings. 

 

 

 

Hmm.  I wonder if this explains any of GM making axles for T1 in addition to AAM.  When T1 launched GM added a second axle supplier, themselves into the mix.  Perhaps someone was on to some sort of issues with AAM then?  I do recall we did lots of rear end work on the K2XX trucks.  Warped axle shafts and all sorts of other rear end issues the first 2-3 years into K2XX production.  

 

All kinda tracks to GM (and other OEMs) selling off their suppliers and not maintaining some sort of involvement with them instead of owning them.  See Boeing and Spirit Aerosystems in where Boeing sold off Spirit and in turn the 737 Max issues that have been going on.  

Edited April 30, 2025 by newdude

[newdude]

From that Carscoops article:

 

Engine teardowns have identified two primary root causes of failure. These are said to include “rod-bearing damage from sediment on connecting rods and crankshaft-oil galleries” as well as “out of specification crankshaft dimensions and surface finish.”

 

 

So perhaps anyone who dumped oil early on might get lucky if they had debris, but no amount of oil changes would fix the out of spec cranks.  

 

[Snow White]

Quote

First and foremost, said incorrectly manufactured parts were supplied by American Axle & Manufacturing and Questum Macimex. According to General Motors, both suppliers introduced manufacturing improvements on or before June 1, 2024 to address quality issues.  American Axle & Manufacturing produced connecting rods with rod bearing damage from sediment, and a similar concern was identified with the crankshaft oil galleries produced by Questum Macimex. The crankshaft supplier is also listed with out-of-spec crankshaft dimensions and surface finish.

GM Recalls Nearly 600,000 Trucks and SUVs Due to L87 Small-Block V8 Manufacturing Defects - autoevolution

RCLRPT-25V274-1598.PDF

 

SUMMARY

so AAM (metaldyne ugghh vomit) owns the rod problem and Questum owns the crank problems which pans out...

Questum was a 2022 GM supplier of the year.... i wouldn't get to fixated on that though, everyone gets a trophy...

 

also, a supervisor at Questum makes about $9.50 an hour as a point of reference and a cnc operator makes $3.83 an hour.  the same US employees make $36/hr and $18/hr respectively.

Edited April 29, 2025 by Snow White
FORMATTING

[Grumpy Bear]

And now we have proof it is dimensional and not metallurgy. 

 

https://apnews.com/article/gm-recall-engine-failure-cadillac-gmc-3472a0a11e0b048ea4c43f7c438bf980

[MrLeadFoot]

4 minutes ago, Grumpy Bear said:

And now we have proof it is dimensional and not metallurgy. 

 

https://apnews.com/article/gm-recall-engine-failure-cadillac-gmc-3472a0a11e0b048ea4c43f7c438bf980

I'm curious as to how they know it's only 3% of the 600k engines. 

[tjonesdfw]

9 hours ago, MrLeadFoot said:

I'm curious as to how they know it's only 3% of the 600k engines. 

GM's already at nearly 5%, just with the 28,101 reports related to this issue to date, assuming that's based on 597,630 stateside vehicles that are part of the recall.  While its correct that only 2-3% had "loss of propulsion," that number doesn't appear to capture ALL the failed L87s under this investigation, just the vehicles that have been reported to be on the road driving when they failed.   Clearly there are more vehicles out there that haven't failed yet; some I personally know have just had failures in recent weeks.  Hard to say what the percentage actually is, but I'd gamble its well north of 5%.

[Black02Silverado]

Explains why not the 2019-2020's

 

https://gmauthority.com/blog/2025/04/gm-explains-why-6-2l-v8-l87-engine-recall-doesnt-apply-to-2019-2020-vehicles/

[Steve-2019]

2 hours ago, Black02Silverado said:

Explains why not the 2019-2020's

 

https://gmauthority.com/blog/2025/04/gm-explains-why-6-2l-v8-l87-engine-recall-doesnt-apply-to-2019-2020-vehicles/

 

Thanks Nick! 

[PunchT37]

Sediments and crank dimensions/ finish. After all these model years, I wonder why the Camaro and Vette 6.2`s are fine?