BREAKING: GM is officially recalling the L87

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viven44

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I mean GM has apparently had 3-4 internal investigations and at least 2 other internal Customer Satisfaction bulletins about these problems and it was not until the heat was brought on by the NHTSA that some level of deep investigation seemed to uncover the root cause of 3 years of problems with this engine.

Yeah it wouldn’t surprise me if they had internal camps arguing over 0W-20 vs 0W-40 for the L87s thus the inaction until it was too late. Ideally it would need a good accelerated reliability study (if that is even possible for engines?) before releasing a new process. I wonder how much “sameness check” and internal qualification was done before this other crank supplier was allowed to RTP (release to production) on L87 platform.
 
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Marky Dissod

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... is an engine with high mileage more likely OK / in-95%-good-group, since it's run smoothly this many miles?
OR
do the recall defects run a range of 'a little bad - failure at 90K' to 'worst bad - failure at 2K'?

Anyone have a sense or data on the range of severity of the defect that's causing the recall?
Is there a mileage point where it's clearly not damaged at manufacture?
You're hoping that, past a certain number of miles, you can lean back?
Wrong questions ...

Plenty of british bulldogs make it to seniority without getting hip dysplasia,
but just because yours is 9 years old with no hip dysplasia,
doesn't mean it will not get hip dysplasia - they're always more likely to get it.

Either change the oil more often and seriously consider 0W30 / 5W30 / 0W40 / 5W40 (think L8T / LT1 motor oils),
or figure out how to have GM replace your suspect L87 with a non-suspect L87 -
your L87 will always be suspect, even after 150,001 miles.
If it makes it to 200,000 miles, then you can pop the bubbly.

Those of you who get their L87s examined by GM:
they will likely not tell you if your engine 'barely passed' with a 70.01 / 100 -
they'll just tell you it 'passed'.
 

Blackcar

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Back in the day when GM had most production in house reliability checks and processes were watched constantly but with the outsourcing lead to what they call thumbs up where a vendor sends part in that is checked for correct dimensions and matches blueprint for surface finish hardness spec etc.
Then the part can flow in without going thru Quality control unless a problem shows up and then part is reassessed.
Saves money??
 

WalleyeMikeIII

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@WalleyeMikeIII


Understand that this estimated percentage with the defect was based on vehicle having engines fail that caused a lack of propulsion. And I would guess GM was able to make this number look as small as they could with a straight face. This is probably only engines that failed under Warranty and probably only within the US. There are a number of these engines that have failed outside of the warranty window and outside of the US that more than likely are not factored into the "count".

There are credible reports of 28,000-30,000 6.2l l87 engines that have had to been replaced. So this is more closer to 5-6% of the overall vehicle population.
Is there published information that the manufacturer thinks the defect percentage is >3%. Might it be, absolutely. Or, perhaps, GM did a population sampling or knows the true source of the defect to be a certain machine or machines used in the mfg process, and they know how many cranks went down it. Perhaps they also know how many cranks had sediment left in the shaft after casting and machining...

I really don't desire to start an argument about it, or go on any assumptions. I am simply stating the publicly available information that we can at least rely on. You correctly quoted the NHTSA report, which is what I am referencing. I guess they never really defined the "defect" in that report, so maybe we are assuming the wrong thing? Are we sure that means 3% of vehicles will have engine failure? Or does it mean 3% of vehicles have defets in the engine that can cause loss of propulision, specifically the two called out in the report: sediment left in oil galleries, and out of tolerance cranks?

Heck, maybe less than 3% have out of tolerance cranks, since some fail for sediment?
You can choose to believe what you want, but this is a larger problem that GM "claims". They are not going to volunteer any more information than they are required and like any large corporation they will "spin" the story in a way that is favorable for them.

I mean GM has apparently had 3-4 internal investigations and at least 2 other internal Customer Satisfaction bulletins about these problems and it was not until the heat was brought on by the NHTSA that some level of deep investigation seemed to uncover the root cause of 3 years of problems with this engine.

None of us will ever know the entire story or the full percentage of failures, but do not kid yourself that GM is really telling the full truth about this problem.

The Drive - GM Engine Failures
It may well be a bigger issue, we will see. But, to me, 3% to 5% is relatively the same magnitude of problem.. The point is, nobody is saying every single crankshaft is out of tolerance, so we have to at least go on facts we have.
 

Stbentoak

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It may well be a bigger issue, we will see. But, to me, 3% to 5% is relatively the same magnitude of problem.. The point is, nobody is saying every single crankshaft is out of tolerance, so we have to at least go on facts we have.
The magnitude of the problem is from MY 21 to 24. The problem is without traceability if "anything" is suspect they have to assume that "everything" is suspect. Three to five percent might be the failure rate, but not the extent of the problem. The other parts supplied over the three-year period could be anywhere from perfectly to specification, all the way up to completely out of specification, but still functioning. What you are seeing out in the world are the ones that have and currently are failing because it's just their point in time to fall apart..... that time could be 7000 miles, 37,500 miles, or 129,342 miles depending on how you treat them, how you maintain them, and mainly the luck of the draw of the combination of parts you have. GM is trying to walk a fine line between replacing things, trying to keep things going with different oil, and warrantying them to a certain point..... but just a certain point to limit their liability.

The ultimate question is how this could have gone on for three whole years? And this has been going on most likely for quite a few years while behind closed doors. I had heard of engines failing clear back in 2022 for let's say "unknown" reasons.....
 

DuraYuk

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The magnitude of the problem is from MY 21 to 24. The problem is without traceability if "anything" is suspect they have to assume that "everything" is suspect. Three to five percent might be the failure rate, but not the extent of the problem. The other parts supplied over the three-year period could be anywhere from perfectly to specification, all the way up to completely out of specification, but still functioning. What you are seeing out in the world are the ones that have and currently are failing because it's just their point in time to fall apart..... that time could be 7000 miles, 37,500 miles, or 129,342 miles depending on how you treat them, how you maintain them, and mainly the luck of the draw of the combination of parts you have. GM is trying to walk a fine line between replacing things, trying to keep things going with different oil, and warrantying them to a certain point..... but just a certain point to limit their liability.

The ultimate question is how this could have gone on for three whole years? And this has been going on most likely for quite a few years while behind closed doors. I had heard of engines failing clear back in 2022 for let's say "unknown" reasons.....
It took toyota the king of reliability 2.5 whole years before they took action while engines were failing under warranty.



These things take time. No way around it. Data needs to be compiled and a fix needs to be found out.

The estimated percentage with defect was at 1% according to nhtsa documents for what its worth.

But the document also states toyota had no idea how many actually were affected and the 1% was just a placeholder on the document.

And toyota 'outsourced' the engines to toyota manufacturing in Huntsville, Alabama. I guess what they say is true about US manufacturing ;)

Mexico is out and now US.....that leaves CANADA! ;)

Or its just a mistake and mistakes happen in manufacturing. Naw! Its a conspiracy! Lmao :)
 

WalleyeMikeIII

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The magnitude of the problem is from MY 21 to 24. The problem is without traceability if "anything" is suspect they have to assume that "everything" is suspect. Three to five percent might be the failure rate, but not the extent of the problem. The other parts supplied over the three-year period could be anywhere from perfectly to specification, all the way up to completely out of specification, but still functioning. What you are seeing out in the world are the ones that have and currently are failing because it's just their point in time to fall apart..... that time could be 7000 miles, 37,500 miles, or 129,342 miles depending on how you treat them, how you maintain them, and mainly the luck of the draw of the combination of parts you have. GM is trying to walk a fine line between replacing things, trying to keep things going with different oil, and warrantying them to a certain point..... but just a certain point to limit their liability.

The ultimate question is how this could have gone on for three whole years? And this has been going on most likely for quite a few years while behind closed doors. I had heard of engines failing clear back in 2022 for let's say "unknown" reasons.....
What data do you have that says this is without traceability?
 

Vladimir2306

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My 2021 Yukon 6.2L has 61K - my VIN comes up on the recall with "no remedy yet".

My question.... is an engine with high mileage more likely OK/in-95%-good-group since it's run smoothly this many miles? OR are do the recall defects run a range of 'a little bad - failure at 90K' to 'worst bad - failure at 2K'.

I think @Vladimir2306 failure was 70K?

Anyone have a sense or data on the range of severity of the defect that's causing the recall? Is there a mileage point where it's clearly not damaged at manufacture?
I mean 70K miles, or 120K km
 

viven44

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What data do you have that says this is without traceability?

It’s there

Affected population 3-6%

But….

They are applying the fix to 100% of population built 2021-2024 (replace engine or move to 0W-40)

Possible explanations
1) can’t trace thus apply fix to 100% of population (safer and politically correct explanation)

#2 is a big taboo and any suggestion of this would be either labeled as misinformation or conspiracy so I’m taking a big risk here

2) 0W-40 was the correct oil for reliability on these L87s for the nominal design targets (finish, clearances)
 

Stbentoak

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What data do you have that says this is without traceability?
Are the parts in question serialized and batch/lot traceable back to raw material certifications and HT/ tensile tests? Is there SPC data available controlling critical characteristics that are failing? Are the critical dimensions specified on the part drawing as "CTQ" (critical to quality) and the process "in control" and supported by data or 100% inspected pass/fail and verified? ..... and a considered a "Frozen" process that can only be deviated by customer permission (No changing of tools, machines, feeds, speeds, process order, etc) and audited by GM? On a regular basis?

If these items are not in place and lot/batch serialized and traceable then you are about 25 years behind modern mfg. What could be worse than this is..... this either it wasn't happening and should have been, or it WAS happening, and no one was paying attn to the data.....
 

Stbentoak

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Or its just a mistake and mistakes happen in manufacturing. Naw! Its a conspiracy! Lmao :)
Mistakes DO happen in MFG... DAILY.... BUT

Competent suppliers/mfgs catch these at the source (and quickly) and contain them before they EVER leave their factory. And the line STOPS till we can assure 100% quality is going out the door..... then make CHANGES to foolproof these new processes/inspection techniques to avoid it ever happening again.

I don't buy the 3-year timeline... I made thousands of parts a day at my business and the worst thing that happened is the day shift caught the night shift reading or checking something wrong. When that happened, we STOPPED and went back thru everything that was made previously till we got back to good parts in the box. Nonconforming parts were either fixed or scrapped. We then lost money. You only go as fast as what makes conforming parts... never faster.

I'm saying GM either trusted the supplier's word/certifications that the parts were good, and they really weren't, or they never audited their processes well enough to assure they could actually produce 100% quality on a high-volume basis..... A lot of supplier's "talk" a good game, but in the heat of the battle.... "WE CAN'T STOP THE LINE !!!!"
 

vcode

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What data do you have that says this is without traceability?
I'm sure there is traceability, but I don't think that matters. Unless you are inspecting parts 100% and documenting the results, traceability may not help any. Is every journal on every crank inspected for microfinish? I don't think they can trace a specific crank to a specific engine anyways.
 
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WalleyeMikeIII

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Are the parts in question serialized and batch/lot traceable back to raw material certifications and HT/ tensile tests? Is there SPC data available controlling critical characteristics that are failing? Are the critical dimensions specified on the part drawing as "CTQ" (critical to quality) and the process "in control" and supported by data or 100% inspected pass/fail and verified? ..... and a considered a "Frozen" process that can only be deviated by customer permission (No changing of tools, machines, feeds, speeds, process order, etc) and audited by GM? On a regular basis?

If these items are not in place and lot/batch serialized and traceable then you are about 25 years behind modern mfg. What could be worse than this is..... this either it wasn't happening and should have been, or it WAS happening, and no one was paying attn to the data..
I know what traceability is.

But you haven't stated what data you have that makes you think they are not? It is possible there are serial numbers on the crankshafts that are scanned when the engine is assembled, such that they know what crank went it which engine...it is also possible they have no clue. But I don't have any data that says one way or another if that is the case or not. (The S/N doesn't necessarily have to be stamped into the crank, it could be on the packaging, etc).
 

vcode

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There is no assumptions.

Look up the word before you use it.

If you look at the links and subjects I posted you will see that reducing viscosity does nothing for supporting the proper eccentricity ratio of a bearing.

The dimensions of the bearing are set or fixed since the LS days. Therefore the only parameter changing is load and viscosity.

Lowering viscosity increases eccentricity ratio.

The limit of this is a ratio of 1 which is technically metal to metal contact.

This is not an assumption.

You are conflating a logical deduction with an assumption.
Load and viscosity are not the only parameters changing. Improperly machined cranks and excess debris in oil passages are actually the only parameters that have changed. If GM specs 16 micro inches for their finish on crank journals and they got 63 instead, bad things are going to happen.
 

DuraYuk

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Mistakes DO happen in MFG... DAILY.... BUT

Competent suppliers/mfgs catch these at the source (and quickly) and contain them before they EVER leave their factory. And the line STOPS till we can assure 100% quality is going out the door..... then make CHANGES to foolproof these new processes/inspection techniques to avoid it ever happening again.

I don't buy the 3-year timeline... I made thousands of parts a day at my business and the worst thing that happened is the day shift caught the night shift reading or checking something wrong. When that happened, we STOPPED and went back thru everything that was made previously till we got back to good parts in the box. Nonconforming parts were either fixed or scrapped. We then lost money. You only go as fast as what makes conforming parts... never faster.

I'm saying GM either trusted the supplier's word/certifications that the parts were good, and they really weren't, or they never audited their processes well enough to assure they could actually produce 100% quality on a high-volume basis..... A lot of supplier's "talk" a good game, but in the heat of the battle.... "WE CAN'T STOP THE LINE !!!!"
Id be there with you but it took toyota 2.5 years to do the same. Toyota created the Lean process everyone uses. If it took them that long it will take everyone a bit of time. In other words if the king of TPS took 2.5 years im not surprised it takes anyone else longer.

 
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Stbentoak

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I'm sure there is traceability, but I don't think that matters. Unless you are inspecting parts 100% and documenting the results, traceability may not help any. Is every journal on every crank inspected for microfinish? I don't think they can trace a specific crank to a specific engine anyways.
Of course it matters....it could reduce their exposure to the problem greatly if they could pinpoint the bad parts and trace them to engines and owners. Would you rather replace 600k engines or 83472 because you know? Absolutely they can trace a crank to a specific engine if GM requires it, and that's a big IF !

I know what traceability is.

But you haven't stated what data you have that makes you think they are not? It is possible there are serial numbers on the crankshafts that are scanned when the engine is assembled, such that they know what crank went it which engine...it is also possible they have no clue. But I don't have any data that says one way or another if that is the case or not. (The S/N doesn't necessarily have to be stamped into the crank, it could be on the packaging, etc).
Traceability S/N's and barcodes (yes, they can blow a barcode on a part with a laser in about 5 seconds) can be laser applied right on the Assy line. That same code can be scanned/logged as the engine is built. Putting it on a package doesn't cut the mustard in this case.
It should be easy enough for someone on here to show us a part/ bad parts with traceable # on them if they exist. If they knew these numbers and could track bad parts, they would be contacting individual owners and not the masses....
 

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