BREAKING: GM is officially recalling the L87

[Marky Dissod]

GM knows the answers, wish they would share.

ONE of the answers - this one is not really any carmaker's fault individually - is break-in oil changes.
Depending on how well the engine is spec'd machined and assembled, it may not be unreasonable to change the oil 7x by 15,000 miles.

What GM is partially to blame for / What is GM's fault principally / What is GM's responsibility entirely
is the substandard machining and assembly. There is no motor oil, no oil change schedule, that could make up for that.

 

[JayceeP]

Is there any credible insight around which plants produced the faulty 6.2 engine’s or is it all 3 North American plants? If you google/AI it, St Catharine’s, ON comes up and so does Tonawanda, NY but not the Tennessee plant. Just curious? And if so, how can you tell?

 

[WalleyeMikeIII]

Is there any credible insight around which plants produced the faulty 6.2 engine’s or is it all 3 North American plants? If you google/AI it, St Catharine’s, ON comes up and so does Tonawanda, NY but not the Tennessee plant. Just curious? And if so, how can you tell?

Best Credible Data says it doesn't matter what plant produced it, it was down to 2 manufacturers of crank shafts and rods, see here --> https://static.nhtsa.gov/odi/rcl/2025/RCLRPT-25V274-1598.PDF (pg 4, "Description of the Cause"; pg 5, Chronology)

And here for the suppliers of Rods and Cranks --> https://static.nhtsa.gov/odi/rcl/2025/RMISC-25V274-5056.pdf

Suggestion to all readers of this tread, go to NHTSA's web site and read all the associated documents for the engine recall, it answers a bunch of questions, and likely creates more...but this is all the publicly available info available.

Select the link below, click "Engine Failure" then explore the documents (referenced two of them above).

https://www.nhtsa.gov/vehicle/2022/GMC/YUKON%252520XL/SUV/4WD#recalls

 

[Vladimir2306]

Best Credible Data says it doesn't matter what plant produced it, it was down to 2 manufacturers of crank shafts and rods, see here --> https://static.nhtsa.gov/odi/rcl/2025/RCLRPT-25V274-1598.PDF (pg 4, "Description of the Cause"; pg 5, Chronology)

And here for the suppliers of Rods and Cranks --> https://static.nhtsa.gov/odi/rcl/2025/RMISC-25V274-5056.pdf

Suggestion to all readers of this tread, go to NHTSA's web site and read all the associated documents for the engine recall, it answers a bunch of questions, and likely creates more...but this is all the publicly available info available.

Select the link below, click "Engine Failure" then explore the documents (referenced two of them above).

https://www.nhtsa.gov/vehicle/2022/GMC/YUKON%252520XL/SUV/4WD#recalls

only at the same time, GM did not change either the connecting rod liners or the crankshaft. Why? Maybe because they realize that they're not the reason?

 

[Vladimir2306]

Один из ответов — и в этом нет вины ни одного из автопроизводителей — это своевременная замена масла во время обкатки.
В зависимости от качества изготовления и сборки двигателя, замена масла 7 раз на каждые 15 000 миль может быть вполне оправданной.

В чём частично виновата GM / В чём основная вина GM / В чём заключается вся ответственность GM
Причина кроется в некачественной обработке и сборке. Никакое моторное масло, никакой график замены масла не смогут это компенсировать.

100%

 

[WalleyeMikeIII]

only at the same time, GM did not change either the connecting rod liners or the crankshaft. Why? Maybe because they realize that they're not the reason?

I believe they did not change any part numbers, nor the design. I do believe they made process changes to address out of tolerance crankshaft machining and rod and crank cleanliness. My guess is they also increased frequency of incoming material inspection for those issues. Was this sufficient to resolve the problems; only time will tell. Is there some other design issue as well — we may not learn that for some time.

 

[Vladimir2306]

I believe they did not change any part numbers, nor the design. I do believe they made process changes to address out of tolerance crankshaft machining and rod and crank cleanliness. My guess is they also increased frequency of incoming material inspection for those issues. Was this sufficient to resolve the problems; only time will tell. Is there some other design issue as well — we may not learn that for some time.

I assure you 100%, they haven't changed anything, unfortunately.

 

[zbad55]

I believe they did not change any part numbers, nor the design. I do believe they made process changes to address out of tolerance crankshaft machining and rod and crank cleanliness. My guess is they also increased frequency of incoming material inspection for those issues. Was this sufficient to resolve the problems; only time will tell. Is there some other design issue as well — we may not learn that for some time.

As I have posted before, yes you are correct and teams of GM people (Engineers,Quality etc.) were sent to Mexico to get this fixed as quick as they could. As far as I know there were not any part number changes, they just break pointed the problem cranks.

 

[West 1]

In the tear down video at Daves it showed rod bearing clearance was .0024 to .0025 while GM recommended 0-20W synthetic oil?

Toyota was holding rod clearances to .0015 as I recall to run the thin oils in synthetics.

Back in the late 90's early 2000 years many race teams switched to synthetic oils. Most were running 20-50W at that time.
We saw many engine bearing failures to the teams that switched to synthetics with no changes in the engines.

At that time a lot of examination was done to determine what happened. The failing engines were found to be running mostly .003 rod and main clearances. Worked fine for years running standard oils at 20-50W. Lots of these teams ran engines to 7500-8500 RPM.

The solution for those running synthetic oils was to tighten up the rod and main clearances. New standard was .00225 to .00250. Rods and main bearing failures went away. This was running 20-50W synthetic oil in race engines.

Toyota was working very hard to improve NVH, Noise, Vibration and Harmonics and they decided the tight bearing clearances could reduce NVH so they pioneered this. Many have followed their lead, they did this way back, maybe 2010 time frame.

Gm is still running .0024 clearances in 2025 and has dropped the oil weight to 0-20W. Based on what we learned 25 years ago I suspect .0024 is too loose for the 0-20W oil.

With all these thoughts out there the engine bearings shown in the video had contamination damage, NOT clearance issues. The source of that crud in the oil pan will show the reason the engines are failing. The clearance issue may shorten the engine life but did not cause early failure.

Frequent initial oil changes do help get contamination out of a new engine, there will always be some in there. The Engine in the tear down video had far too much in there and it did not come from those bearings with minor scrape marks on them.

Maybe the New Blocks had oil passages not properly cleaned before engine build? Maybe the crankshafts were not properly cleaned after the grinding and polishing was done? Something brought the contamination into these engines at the factory.

Still hoping for a good honest response from GM.

 

[WalleyeMikeIII]

In the tear down video at Daves it showed rod bearing clearance was .0024 to .0025 while GM recommended 0-20W synthetic oil?

Toyota was holding rod clearances to .0015 as I recall to run the thin oils in synthetics.

Back in the late 90's early 2000 years many race teams switched to synthetic oils. Most were running 20-50W at that time.
We saw many engine bearing failures to the teams that switched to synthetics with no changes in the engines.

At that time a lot of examination was done to determine what happened. The failing engines were found to be running mostly .003 rod and main clearances. Worked fine for years running standard oils at 20-50W. Lots of these teams ran engines to 7500-8500 RPM.

The solution for those running synthetic oils was to tighten up the rod and main clearances. New standard was .00225 to .00250. Rods and main bearing failures went away. This was running 20-50W synthetic oil in race engines.

Toyota was working very hard to improve NVH, Noise, Vibration and Harmonics and they decided the tight bearing clearances could reduce NVH so they pioneered this. Many have followed their lead, they did this way back, maybe 2010 time frame.

Gm is still running .0024 clearances in 2025 and has dropped the oil weight to 0-20W. Based on what we learned 25 years ago I suspect .0024 is too loose for the 0-20W oil.

With all these thoughts out there the engine bearings shown in the video had contamination damage, NOT clearance issues. The source of that crud in the oil pan will show the reason the engines are failing. The clearance issue may shorten the engine life but did not cause early failure.

Frequent initial oil changes do help get contamination out of a new engine, there will always be some in there. The Engine in the tear down video had far too much in there and it did not come from those bearings with minor scrape marks on them.

Maybe the New Blocks had oil passages not properly cleaned before engine build? Maybe the crankshafts were not properly cleaned after the grinding and polishing was done? Something brought the contamination into these engines at the factory.

Still hoping for a good honest response from GM.

This is great info. Thank you for sharing. Pg 4 of the NHTSA Investigation implies they attribute the sediment to bad cleaning on rods and crankshafts, and I believe this is the soruce of the stuff in the Dave's engine...the early life fails. The fails in higher mileage engines 25-40k+ are likely attibuted to the poor crank finish interacting w/ the bearings...thoughts?

 

[TrueAt1stLight]

In the tear down video at Daves it showed rod bearing clearance was .0024 to .0025 while GM recommended 0-20W synthetic oil?

Toyota was holding rod clearances to .0015 as I recall to run the thin oils in synthetics.

Back in the late 90's early 2000 years many race teams switched to synthetic oils. Most were running 20-50W at that time.
We saw many engine bearing failures to the teams that switched to synthetics with no changes in the engines.

At that time a lot of examination was done to determine what happened. The failing engines were found to be running mostly .003 rod and main clearances. Worked fine for years running standard oils at 20-50W. Lots of these teams ran engines to 7500-8500 RPM.

The solution for those running synthetic oils was to tighten up the rod and main clearances. New standard was .00225 to .00250. Rods and main bearing failures went away. This was running 20-50W synthetic oil in race engines.

Toyota was working very hard to improve NVH, Noise, Vibration and Harmonics and they decided the tight bearing clearances could reduce NVH so they pioneered this. Many have followed their lead, they did this way back, maybe 2010 time frame.

Gm is still running .0024 clearances in 2025 and has dropped the oil weight to 0-20W. Based on what we learned 25 years ago I suspect .0024 is too loose for the 0-20W oil.

With all these thoughts out there the engine bearings shown in the video had contamination damage, NOT clearance issues. The source of that crud in the oil pan will show the reason the engines are failing. The clearance issue may shorten the engine life but did not cause early failure.

Frequent initial oil changes do help get contamination out of a new engine, there will always be some in there. The Engine in the tear down video had far too much in there and it did not come from those bearings with minor scrape marks on them.

Maybe the New Blocks had oil passages not properly cleaned before engine build? Maybe the crankshafts were not properly cleaned after the grinding and polishing was done? Something brought the contamination into these engines at the factory.

Still hoping for a good honest response from GM.

Yeah- that’s a freakin’ BLOCKBUSTER post, and quite possibly the best I’ve read in this entire thread. Thanks for posting, @West 1

 

[Vladimir2306]

In the tear down video at Daves it showed rod bearing clearance was .0024 to .0025 while GM recommended 0-20W synthetic oil?

Toyota was holding rod clearances to .0015 as I recall to run the thin oils in synthetics.

Back in the late 90's early 2000 years many race teams switched to synthetic oils. Most were running 20-50W at that time.
We saw many engine bearing failures to the teams that switched to synthetics with no changes in the engines.

At that time a lot of examination was done to determine what happened. The failing engines were found to be running mostly .003 rod and main clearances. Worked fine for years running standard oils at 20-50W. Lots of these teams ran engines to 7500-8500 RPM.

The solution for those running synthetic oils was to tighten up the rod and main clearances. New standard was .00225 to .00250. Rods and main bearing failures went away. This was running 20-50W synthetic oil in race engines.

Toyota was working very hard to improve NVH, Noise, Vibration and Harmonics and they decided the tight bearing clearances could reduce NVH so they pioneered this. Many have followed their lead, they did this way back, maybe 2010 time frame.

Gm is still running .0024 clearances in 2025 and has dropped the oil weight to 0-20W. Based on what we learned 25 years ago I suspect .0024 is too loose for the 0-20W oil.

With all these thoughts out there the engine bearings shown in the video had contamination damage, NOT clearance issues. The source of that crud in the oil pan will show the reason the engines are failing. The clearance issue may shorten the engine life but did not cause early failure.

Frequent initial oil changes do help get contamination out of a new engine, there will always be some in there. The Engine in the tear down video had far too much in there and it did not come from those bearings with minor scrape marks on them.

Maybe the New Blocks had oil passages not properly cleaned before engine build? Maybe the crankshafts were not properly cleaned after the grinding and polishing was done? Something brought the contamination into these engines at the factory.

Still hoping for a good honest response from GM.

You wrote everything right. But. There is one but. Gm violated its standards for clearances, and in fact they are completely absent in some places.

 

[West 1]

I had not seen the Pg 4 of the NHTSA Investigation posted here. Very good information and shows there is awareness of the problem. I believe GM reported the crankshafts were not finished correctly, maybe hidden in that statement is they were not cleaned after grinding which exposes the new engines to early failure issues? Very hard to believe this could have gone on for several years.

I was a ware of a similar issue that happened at Ford, they were finish polishing crankshafts in house at the engine assembly plant. The crank polisher broke down on one shift so the new un polished crankshafts were stacked on pallets just like they did for crankshafts when they were finished. The second shift came in and grabbed the un finished crankshafts and installed them in engines all night long. More than a thousand bad cranks were installed. In the morning shift they went to get the un finished crankshafts to get them polished and discovered the mistake. Cost them a lot of money and time to go find all those engines and get them back for testing and repair. In Fords case twenty years ago this was a 1 shift error and it was caught. In GM's case they did this for years. I really can't see how that can happen today.

 

[Blackcar]

Years ago, they were ground in house and inspected 100% now they come in what they call thumbs up go right to assembly.

Thumbs up the vendor send part into Quality Control they inspect dimensions, surface finish, etc. if parts ok, they don't inspect from then on that's where word thumbs up came from.

 

[WalleyeMikeIII]

Years ago, they were ground in house and inspected 100% now they come in what they call thumbs up go right to assembly.

Thumbs up the vendor send part into Quality Control they inspect dimensions, surface finish, etc. if parts ok, they don't inspect from then on that's where word thumbs up came from.

Often this type of process has some “incoming quality inspection” on an occasional basis. Maybe 2 of every 500 or so.

My guess is for a while after the MFG process changes, there was 100% visual inspection for debris, and a stepped up full inspection to maybe 5% of parts in each lot. But I am just conjecturing, not super familiar with GM’s internal processes.

 

[DontTaseMeBro]

From Perplexity...

"100% synthetic vs Fully Synthetic.​

Core answer: The terms “100% synthetic” and “fully synthetic” are often used interchangeably in the motor-oil industry, but exact definitions vary by brand and labeling rules. In practice, most oils labeled as fully synthetic or 100% synthetic are built from synthetic base oils and modern additives, with the distinction sometimes reflecting the base-oil mix rather than overall performance."

joe

Yes the terms might be used interchangeably if they’re referring to oils from the same group. However -

• "Full Synthetic" vs. "100% Synthetic" (Marketing Distinction): Some brands use "Full Synthetic" to denote oils from Group III base stocks (highly refined, but technically synthetic), while "100% Synthetic" might be reserved for oils using more premium Group IV (PAO) or Group V (Ester) base oils, which offer superior performance.
• "Full Synthetic" as a Blend: In some cases, "Full Synthetic" might refer to a blend with a high percentage of synthetic but still containing some mineral oil, while "100% Synthetic" more strictly means no mineral oil at all.

And this was what I was alluding to. You’ll have group III oil marketed as full synthetic or even a blend. That’s why the 100% synthetic is a no if ands or buts distinction vs fully synthetic.

 

[tagexpcom]

Ran across this youtube, talking about a list of dubious engines. #3 is the 6.2L L87 - old news here. However at 12:34 into the youtube it calls out years 2019 and 2020 as having issues which is outside the 2021-2024 recall window. I know everyone is watching 2025... but wondering if there's any truth to this going back to 2019.

 

[vcode]

Ran across this youtube, talking about a list of dubious engines. #3 is the 6.2L L87 - old news here. However at 12:34 into the youtube it calls out years 2019 and 2020 as having issues which is outside the 2021-2024 recall window. I know everyone is watching 2025... but wondering if there's any truth to this going back to 2019.

I wonder if they are talking about valvetrain issues with the 2019-20's? They really don't clarify....

 

[zbad55]

I wonder if they are talking about valvetrain issues with the 2019-20's? They really don't clarify....

I posted this in another thread that explains to possible recall expansion to include the some 2019's and 2020's

 

[07Burb]