BREAKING: GM is officially recalling the L87

[GMCnewbee]

Some of yall need to stop what your doing and apply to General Motors to be engineers. Whether you have the credentials or not yall are convinced you know better.

Hurry and on board so we can fix the issues the engineers they have seemingly dont understand.

Seems like we have 100 pages of waste here. Just back and forth..

It will be interesting to see what happens in the next year or so. Whether the 0w40 switched engines fail or not. I bet at least 25% do within that extended warranty period.

Not that it matters but there have now been over 200 pages on this thread. I don't know what happened to the first 100 pages. I guess we broke some kind of limit and the data got dumped? There was a lot of good stuff in those first 100 pages.

 

[Fless]

Not that it matters but there have now been over 200 pages on this thread. I don't know what happened to the first 100 pages. I guess we broke some kind of limit and the data got dumped? There was a lot of good stuff in those first 100 pages.

@MADDOG would you be able to look into the loss of the original 100-ish pages?

 

[Scarey]

You also tie the political background here

I think your trolling.

 

[vcode]

@MADDOG would you be able to look into the loss of the original 100-ish pages?

Page one starts in April, which I think is the original post. Are pages missing in between?

 

[West 1]

Not sure how this might play into these 6.2L failures but the last time I visited our Piston plant which was in 2018 I think, GM had started buying what they called the Power Cylinder. We manufactured pistons, Rings, bearings, gaskets and more internal engine parts.

GM wanted the Pistons delivered with Rings already on them, Connecting rod installed and the bearings already in the rods. This was the Power Cylinder. At that time only Mahle and Federal Mogul were competing for these orders. Other companies were not set up to provide the power cylinder.
Federal Mogul had a lot of the engine contracts back then.

GM would send blueprints out to the bearing manufacturers and leave it up to them to develop the bearings to meet the GM blueprint. The provider also had to prove to GM that the product met the specs GM provided. In the 1990’s the bearing plant also had development labs, I think the Bearing lab had 8 Dyno cels which had engines running 24/7 to prove parts met the specs. I belive the dyno cels were obsoleted by modern high tech computers that could test the parts virtually rather than in running engines.

Federal Mogul was bought out twice after 2018 and I have no idea if they still do this work, I would expect they do since it was a big part of the profit in that company. About that same time several foreign builders of parts were trying to break into the domestic engine bearing supply. Maybe they did and GM used some of the less tested parts??? It would be very interesting to know where the failures started.

Back in the day we would help evaluate engine failures and you woiuld be amazed at what the engineers could determine from looking at failed parts. I could eyeball the common stuff but they could get out the microscopes and get exact answers many times. People know the exact issue that is taking place but it is very quiet what that actually is.
They had a gun they could shoot a part with and it would come back with exact information on the metalurgy of the part. It used radiation like an exray. Very cool stuff.

I have not read that GM is pointing fingers at a specific supplier of the parts used. YET.

 

[Vladimir2306]

I think your trolling.

Do you have anything to say on the matter?

 

[Stbentoak]

Not sure how this might play into these 6.2L failures but the last time I visited our Piston plant which was in 2018 I think, GM had started buying what they called the Power Cylinder. We manufactured pistons, Rings, bearings, gaskets and more internal engine parts.

GM wanted the Pistons delivered with Rings already on them, Connecting rod installed and the bearings already in the rods. This was the Power Cylinder. At that time only Mahle and Federal Mogul were competing for these orders. Other companies were not set up to provide the power cylinder.
Federal Mogul had a lot of the engine contracts back then.

GM would send blueprints out to the bearing manufacturers and leave it up to them to develop the bearings to meet the GM blueprint. The provider also had to prove to GM that the product met the specs GM provided. In the 1990’s the bearing plant also had development labs, I think the Bearing lab had 8 Dyno cels which had engines running 24/7 to prove parts met the specs. I belive the dyno cels were obsoleted by modern high tech computers that could test the parts virtually rather than in running engines.

Federal Mogul was bought out twice after 2018 and I have no idea if they still do this work, I would expect they do since it was a big part of the profit in that company. About that same time several foreign builders of parts were trying to break into the domestic engine bearing supply. Maybe they did and GM used some of the less tested parts??? It would be very interesting to know where the failures started.

Back in the day we would help evaluate engine failures and you woiuld be amazed at what the engineers could determine from looking at failed parts. I could eyeball the common stuff but they could get out the microscopes and get exact answers many times. People know the exact issue that is taking place but it is very quiet what that actually is.
They had a gun they could shoot a part with and it would come back with exact information on the metalurgy of the part. It used radiation like an exray. Very cool stuff.

I have not read that GM is pointing fingers at a specific supplier of the parts used. YET.

It's called an XRF gun. I was in the machining industry for 40 years, and actually I used to machine pistons for federal mogul. They were right in my town, and they needed a vendor who could machine the bowls in pistons because they didn't have the capacity. They would bring us wire bound crate after wire bound crate daily. We ran them 24 hours a day and this went on for probably six months until they figured out how to increase capacity at their own plant. They were so picky that even machining chips they wanted back and kept separate and brought their own container for us to dump chips into. They recycled them back into new pistons. I had visited that plant a few times and it was a very interesting process. In a nutshell they could go from pouring the casting for a brand-new piston to having a completely finished piston within just a few hours.
We also machined parts for Chrysler Transmission Kokomo IN that went into the all wheel drive units of certain transmissions. Toured that plant also, it was also a marvel to show how bell housings came in in molten aluminum, machined, filled with parts and out the back door in hours....

 

[jfoj]

I think the days of computer modeling and simulation have bypassed the good old days of real world testing (Dyno, track stress testing, daily driving). Most of this is driven by cost cutting and delivery time. The problem with modeling and simulation is if the "Assumptions" for the model or simulation are wrong or unrealistic, the output is wrong and unrealistic!

Additionally gone are the days where every X number unit is pulled from the assembly line, disassembled and inspected for quality and assembly errors. Too much emphasis on "Automated" end of line testing is determined to be more accurate so no need for pulling, disassembling and inspecting assembly line built units.

While there are many good engineers that want to do the best job possible and design reliable and quality products, they continue to be under pressure from the bean counters to cut cost, pressured to shorten design and delivery times, have to deal with government regulations that are typically unrealistic and at being told "good enough" is fine. So we are all suffering from plan obsolescence and sub par reliability. The consumers are now the testing lab for the products the manufacturers deliver and typically at the customers cost and inconvenience.

The end result is the products are way too expensive, way too complicated and overall unreliable and too expensive to repair.

We are all rats in the race!

 

[Scarey]

Do you have anything to say on the matter?

I think you’re a little deeper and darker than a regular troll. You asked!

 

[zbad55]

All engines are not driven under the same conditions and maintained the same, sure there will be engines failing on 0W40, 5W30, 10W40, 20W50, you name it. Some recalled, some not. Lots of variables here.

But the thing that SO MANY fail to understand is the bearing surface loading of the 6.2l exceeds the protection that 0W20 can provide under many operating conditions. So what do you expect when you exceed limits?

As I have stated time and time again, GM did not spec 0W20 for the long term reliability of these engines.

I'm not sure where you get your information from but a lot of it is really not true and just conjecture. As someone who worked for GM for 30 years to think that they spec something that does not work is way off base. As I posted before what the problem was and why the recall happened we would not even be talking about the oil 0-20w or 0-40w in these vehicles if the cranks were machined properly to spec. And yes I still speak with powertrain engineers at GM, as the recall affected me also,

 

[jfoj]

@zbad55,

I get my information from many industry insiders as well as gather information on my own vehicle. Additionally I have spent my entire life from the early age of 13 involved with the automotive industry in many forms.

Understand that many things are chosen or "speced" without the customers best interest in mind. While you may have worked for GM for 30 years, understand a lot of things have changed and continue to change even in the last 5-10 years.

Current engines are putting out much greater power density than they did years ago. The current 6.2l engines put out pretty much the same or more advertised power of the late 1960 to early 1970 big block Chevrolet engines. We could debate if the advertised power and torque of the older big block Chevrolet engines was correct or understated, but current engines are putting out killer HP and Torque at low RPM's. This is putting bearing loading under severe duty and the oil performance calculations show that 0W20 is not up to the task. Will 0W20 oil work in these engines, yes it will for a period of time under more ideal conditions. Take poor maintenance intervals, fuel dilution, heavier loading such as sustained highway operation or towing, you are playing Russian Rolette!

GM had some counter measures in place to combat the lack of safety margin with 0W20 engine oil, but they have started to take these counter measures away. The current bi-metal aluminum bearings are not forgiving at all, they SUX IMHO. GM used to run Teflon coated rod bearings but they foolishly got away from this, last I saw they were still running Teflon coated main bearings.

Market pressures, reducing cost and fuel economy requirements are the main driving factor today. Long term reliability and serviceability are not the #1 focus anymore. Too much plastic and aluminum for weight savings, I mean plastic suspension control arms on some models, give me a break!!

Safety margins are either way too thin or just tossed out the window these days. Too much computer modeling with bad and not real world assumptions and software is being used after the fact to put a square peg in a round hole.

At least Ford is still using 5W30 in a lot of its fleet which is VERY wise. They still have their problems but I doubt they are seeing the bearing failures GM is having.

What I have stated above is totally factual and true, believe what you want to believe. Can things be better designed and can more robust items be "speced" sure can, but there are competing factors that cause all the good ideas to be shut down early on.

I worked for GM for a while and got out while the getting out was good. I saw the train wreck on the way and did not want to be any part of the train wreck.

See my comments here as well - https://www.tahoeyukonforum.com/thr...icially-recalling-the-l87.154084/post-1995948

 

[GMCnewbee]

@MADDOG would you be able to look into the loss of the original 100-ish pages?

I can't but perhaps the Forum Admin could do it. This thread goes much further back than April 2025.

 

[Fless]

I can't but perhaps the Forum Admin could do it. This thread goes much further back than April 2025.

I wasn't asking you, I was tagging a high level admin.

 

[07Burb]

I'm not seeing where any data was lost. The first post shares a link to another post, could that possibly be the info that @GMCnewbee is referring to that he thinks is lost? There is no setting on the forum that just dumps info out of a thread and the only reason we'd split a thread out is if the thread got way off topic and needed to be broken out into two separate threads so I'm not thinking there's anything for us to track down here

 

[zbad55]

@zbad55,

I get my information from many industry insiders as well as gather information on my own vehicle. Additionally I have spent my entire life from the early age of 13 involved with the automotive industry in many forms.

Understand that many things are chosen or "speced" without the customers best interest in mind. While you may have worked for GM for 30 years, understand a lot of things have changed and continue to change even in the last 5-10 years.

Current engines are putting out much greater power density than they did years ago. The current 6.2l engines put out pretty much the same or more advertised power of the late 1960 to early 1970 big block Chevrolet engines. We could debate if the advertised power and torque of the older big block Chevrolet engines was correct or understated, but current engines are putting out killer HP and Torque at low RPM's. This is putting bearing loading under severe duty and the oil performance calculations show that 0W20 is not up to the task. Will 0W20 oil work in these engines, yes it will for a period of time under more ideal conditions. Take poor maintenance intervals, fuel dilution, heavier loading such as sustained highway operation or towing, you are playing Russian Rolette!

GM had some counter measures in place to combat the lack of safety margin with 0W20 engine oil, but they have started to take these counter measures away. The current bi-metal aluminum bearings are not forgiving at all, they SUX IMHO. GM used to run Teflon coated rod bearings but they foolishly got away from this, last I saw they were still running Teflon coated main bearings.

Market pressures, reducing cost and fuel economy requirements are the main driving factor today. Long term reliability and serviceability are not the #1 focus anymore. Too much plastic and aluminum for weight savings, I mean plastic suspension control arms on some models, give me a break!!

Safety margins are either way too thin or just tossed out the window these days. Too much computer modeling with bad and not real world assumptions and software is being used after the fact to put a square peg in a round hole.

At least Ford is still using 5W30 in a lot of its fleet which is VERY wise. They still have their problems but I doubt they are seeing the bearing failures GM is having.

What I have stated above is totally factual and true, believe what you want to believe. Can things be better designed and can more robust items be "speced" sure can, but there are competing factors that cause all the good ideas to be shut down early on.

I worked for GM for a while and got out while the getting out was good. I saw the train wreck on the way and did not want to be any part of the train wreck.

See my comments here as well - https://www.tahoeyukonforum.com/thr...icially-recalling-the-l87.154084/post-1995948

I'm not questioning some of your knowledge or your work history, just some of the statements regarding this issue. And as for being retired it was just recent so not 5 or 10 years ago so I know what goes on at GM and I worked on all major truck programs starting with the GMT800. Is everything good there, nope not at all and I would be the first to admit that, but to say safety margins are thrown out the window is not accurate. . This is an issue that started with the crank journals and machining done in Mexico and not the bearings. From your statement I can see you have a very negative view of GM and that is your opinion, not sure as to what vehicle you have that is affected by this, but as I mentioned this has affected me and yes it does p#$@ me off.

As for your statements regarding computer modeling, yes a lot of this is done on all subsystems for the vehicle. But to suggest that real world testing does not go on anymore or vehicle subsystem tear downs and validation testing is absent is just not true. These major programs are worked on about 5 years in advance before they are ready for saleable production.

 

[jfoj]

@zbad55

I have a 2005 GMC Yukon Denali which I still drive daily (275,000 miles and counting), just had to move it to drive my 2024 GMC Yukon Denali to warm it up to change the oil. My 2024 6.2l Yukon is not within the Recall VIN range. The 6.2l in my Yukon was built July 15, 2024, 2 weeks outside of the recall cut off window. Does this mean I am in the safe zone, it should, but I do not run 0W20 oil in my engine, dumped it at 544 miles and never looking back. Additionally none of the 2024 6.2l have coated rod bearings, I cannot figure out 100% when the coated rod bearings were dropped, I am pretty sure the L86 had coated rod bearings but either with the start of the L87 or early on in the L87 manufacturing window the coated rod bearings were dropped.

I have a very negative view of most of the automotive industry these days. Not just GM but many of the manufacturers. Stupid decisions made daily, many may have started as wise, solid ideas, but by the time deadlines and dollars are questioned, things change quickly. Too many foolish ideas to try and obtain good fuel economy out of 6000 lb vehicles that impacts the drivetrain reliability. I doubt I will ever see anything as reliable as my 2005 6.0l Yukon, went into the dealer 1 time since new for a replacement NAV radio, al other repairs done by me and nothing crazy expensive, the engine and transmission have never been opened up.

When deadlines and dollars run the show, safety margins are tossed out. Does not really what Engineering thinks or wants, they get told to sit down and be quiet. I have seen this many times before and know it still goes on daily in many manufacturers. I have insiders in both US and Japanese manufacturers that I get info from on a regular basis. The Japanese are up against the same deadline and dollar problem as well.

Vehicles have become too expensive and the profit margins have shrunk for the manufacturer and dealers. Not much money made in new vehicles anymore.

Well aware of the crankshaft problems, it had to do with final journal finish which was not smooth enough for 0W20 engine oil. The thinner the engine oil, the smoother the crankshaft journals need to be. If theses engines still had coated rod bearings, the failure rate would be so much lower and there would not likely be a recall on these engines even with the crankshaft surface finish not being smooth enough.

As for safety margin, the reason GM is putting 0W40 in the recalled engines that "Passed" the Pico test is to give more safety margin for bearing life. GM really won't and did not spec 0W40 for replacement engines or the other non recalled engines because the vehicles were certified by the EPA with 0W20 oil AND if GM now pivoted and said all 6.2l and possible 5.3l engines should run 0W40 oil the lawsuits and reimbursements for failed engines that were not covered by warranty would be piling up and GM would likely go broke or at least be in serious trouble for years to come both financially and from buyers going elsewhere.

I am tired of hearing about ALL the MILLIONS of engines run fine on 0W20 oil, some do, but do the math for the bearing loading to see what oil these higher Torque engine should be running and it will not be 0W20.

 

[DuraYuk]

I think the days of computer modeling and simulation have bypassed the good old days of real world testing (Dyno, track stress testing, daily driving). Most of this is driven by cost cutting and delivery time. The problem with modeling and simulation is if the "Assumptions" for the model or simulation are wrong or unrealistic, the output is wrong and unrealistic!

Additionally gone are the days where every X number unit is pulled from the assembly line, disassembled and inspected for quality and assembly errors. Too much emphasis on "Automated" end of line testing is determined to be more accurate so no need for pulling, disassembling and inspecting assembly line built units.

While there are many good engineers that want to do the best job possible and design reliable and quality products, they continue to be under pressure from the bean counters to cut cost, pressured to shorten design and delivery times, have to deal with government regulations that are typically unrealistic and at being told "good enough" is fine. So we are all suffering from plan obsolescence and sub par reliability. The consumers are now the testing lab for the products the manufacturers deliver and typically at the customers cost and inconvenience.

The end result is the products are way too expensive, way too complicated and overall unreliable and too expensive to repair.

We are all rats in the race!

OMG.

Now the computer models are wrong!?

Good grief.

Why are we making up metrics in 2025? Products are way to expensive, way too complicated, and overall unreliable?!

Is any of this based in reality or just 'feels' like 95% of this thread ?

-Yall realize why all those muscle cars and vintage big bodied american cars only had like 10k miles on them before someone parked it with the hood up right? Its because they are so simple, easy to fix that people parked perfectly good cars and bought another. Hell some people kept doing that until they had a collection.

Cars are so unreliable now that the average age of a vehicle on the road is 12.8 years old with average mileage of 160k. These ***** cars and their unreliability. Gimme back an old 6 volt car with a carburetor. Yall and your fancy smancy talking boxes and gizmos. Back in my day we walked 35 miles to school in the blizzard in Dallas Texas one way while it was 100 degrees outside with no sun block.

I love it here.

0w20 Gang rise up!

 

[blanchard7684]

OMG.

Now the computer models are wrong!?

Good grief.

Why are we making up metrics in 2025? Products are way to expensive, way too complicated, and overall unreliable?!

Is any of this based in reality or just 'feels' like 95% of this thread ?

-Yall realize why all those muscle cars and vintage big bodied american cars only had like 10k miles on them before someone parked it with the hood up right? Its because they are so simple, easy to fix that people parked perfectly good cars and bought another. Hell some people kept doing that until they had a collection.

Cars are so unreliable now that the average age of a vehicle on the road is 12.8 years old with average mileage of 160k. These ***** cars and their unreliability. Gimme back an old 6 volt car with a carburetor. Yall and your fancy smancy talking boxes and gizmos. Back in my day we walked 35 miles to school in the blizzard in Dallas Texas one way while it was 100 degrees outside with no sun block.

I love it here.

0w20 Gang rise up!

I don’t see anything in @jfoj post that justifies your mockery.

In fact it is rather dishonest to say he thinks the computer models are wrong.

He is saying the models can be wrong if assumptions that are inputs are wrong. Further that previous established qc methods have fallen out of favor ; and these methods could be useful in verifying the models.

 

[GMCnewbee]

I'm not seeing where any data was lost. The first post shares a link to another post, could that possibly be the info that @GMCnewbee is referring to that he thinks is lost? There is no setting on the forum that just dumps info out of a thread and the only reason we'd split a thread out is if the thread got way off topic and needed to be broken out into two separate threads so I'm not thinking there's anything for us to track down here

All I am saying is that I remember the thread passing 200, then recently it was back to 100. Just what I saw. Am I wrong?

 

[Fless]

I'm not seeing where any data was lost. The first post shares a link to another post, could that possibly be the info that @GMCnewbee is referring to that he thinks is lost? There is no setting on the forum that just dumps info out of a thread and the only reason we'd split a thread out is if the thread got way off topic and needed to be broken out into two separate threads so I'm not thinking there's anything for us to track down here

@GMCnewbee

Am I imagining that each thread used to "page" at 10 posts (post #11 on page 2, etc.), but now it's 20? That would affect the page count.