NHTSA opens preliminary probe into more than 870,000 GM vehicles

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jfoj

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5W30 all day long, worked fine in my 6.0l for 275,000 miles. Sure there are differences, but my 2005 6.0l turns about the same RPM at cruise as my 2024, probably within about 300-400 RPM. The L87 has a 2 stage ECU controlled oil pump, the oil pressure is boosted at higher RPM's. I think the failure is the oil pressure sensor is located at the beginning of the oil flow path, not at the end! This 2 stage pump again is probably for fuel economy reasons to reduce pumping loss. Might consider forcing the oil pump to the high stage, probably can be done by either unplugging the oil pump pressure solenoid wire or providing power to it constantly. Only issue is with this trigger a CEL and cause other side effects?

The 0W oils that all the manufacturers are running is for CAFE requirements and there is only nanonuts increase in fuel economy. Some of the Toyota factory fills are 0W8!!! The issue is with this super thin oil it has less of a chance to keep a film on the bearing journals when the engine is turned off. Additionally I believe the roller bearings in the lifters and the lifter pressures on the camshaft are borderline protected with 0W20. Then add fuel and water contamination into the 0W20 at higher miles and you are lubricating with a contaminated solvent and not oil. Then to add the fact that the oil consumption of the 0W20 is rather high and I think a lot of these engines consistently are running low on oil. I believe the low oil light triggers around 2 quarts low. 0W20 seems to have more cylinder wash with the DI than the slighter heavier oils.

Anyone worried about the DFM functioning with 5W30 vs 0W20 needs to understand the DFM is not likely going to function until the engine is either partially or fully warmed up.

Now where Vladimir is located, he may have temps that could use a 0W engine oil, but I would probably run a 0W30 or 0W40 if I really has crazy low temperatures or run and engine heater if possible.

But one of the more common failures of the 6.2l engine has been front main bearing failure, rod bearing #1 and #2 tend to be either from oil starvation along with the front main or due to debris from the front main failing from what I am gathering from research.

The other craziness is GM claims the DFM may improve fuel economy by 5-20%, well my 2800 mile fuel economy average has been 17.4 MPG with the DFM being disabled. I guess I would be getting closer to 20 MPG if the DFM was not disabled! I somehow doubt I would see this much of a difference, but it is nice to dream.

Anyway it will be interesting to see where the 6.2l problem ends up. I really doubt GM will wholesale replace engines. They may extend the engine Warranty, but this will not satisfy NHTSA from the safety issue of engine failure while driving. If GM can prove that they can alter software to reduce the OCI and possibly detect wear or knocking before the engine seizes, this would be my guess as to what they will try to do.

A software solution for a hardware problem!!
 

Vladimir2306

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5W30 all day long, worked fine in my 6.0l for 275,000 miles. Sure there are differences, but my 2005 6.0l turns about the same RPM at cruise as my 2024, probably within about 300-400 RPM. The L87 has a 2 stage ECU controlled oil pump, the oil pressure is boosted at higher RPM's. I think the failure is the oil pressure sensor is located at the beginning of the oil flow path, not at the end! This 2 stage pump again is probably for fuel economy reasons to reduce pumping loss. Might consider forcing the oil pump to the high stage, probably can be done by either unplugging the oil pump pressure solenoid wire or providing power to it constantly. Only issue is with this trigger a CEL and cause other side effects?

The 0W oils that all the manufacturers are running is for CAFE requirements and there is only nanonuts increase in fuel economy. Some of the Toyota factory fills are 0W8!!! The issue is with this super thin oil it has less of a chance to keep a film on the bearing journals when the engine is turned off. Additionally I believe the roller bearings in the lifters and the lifter pressures on the camshaft are borderline protected with 0W20. Then add fuel and water contamination into the 0W20 at higher miles and you are lubricating with a contaminated solvent and not oil. Then to add the fact that the oil consumption of the 0W20 is rather high and I think a lot of these engines consistently are running low on oil. I believe the low oil light triggers around 2 quarts low. 0W20 seems to have more cylinder wash with the DI than the slighter heavier oils.

Anyone worried about the DFM functioning with 5W30 vs 0W20 needs to understand the DFM is not likely going to function until the engine is either partially or fully warmed up.

Now where Vladimir is located, he may have temps that could use a 0W engine oil, but I would probably run a 0W30 or 0W40 if I really has crazy low temperatures or run and engine heater if possible.

But one of the more common failures of the 6.2l engine has been front main bearing failure, rod bearing #1 and #2 tend to be either from oil starvation along with the front main or due to debris from the front main failing from what I am gathering from research.

The other craziness is GM claims the DFM may improve fuel economy by 5-20%, well my 2800 mile fuel economy average has been 17.4 MPG with the DFM being disabled. I guess I would be getting closer to 20 MPG if the DFM was not disabled! I somehow doubt I would see this much of a difference, but it is nice to dream.

Anyway it will be interesting to see where the 6.2l problem ends up. I really doubt GM will wholesale replace engines. They may extend the engine Warranty, but this will not satisfy NHTSA from the safety issue of engine failure while driving. If GM can prove that they can alter software to reduce the OCI and possibly detect wear or knocking before the engine seizes, this would be my guess as to what they will try to do.

A software solution for a hardware problem!!
I do not believe that the 0w20 oil and the oil pump are to blame, because when the engine breaks down, the oil is left the same 0w20, and the pump is not changed. And after the repair, the engines drive without problems for a long time. And as for oil consumption, on my Yukon we greatly reduced it by replacing the valve covers. Because the old one had a problem with the sealant, unlike the new ones.
By the way, on 6.2 tahoe k2 I drove 160 thousand km on 0w20 oil, without any problems))
 

DontTaseMeBro

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I do not believe that the 0w20 oil and the oil pump are to blame, because when the engine breaks down, the oil is left the same 0w20, and the pump is not changed. And after the repair, the engines drive without problems for a long time. And as for oil consumption, on my Yukon we greatly reduced it by replacing the valve covers. Because the old one had a problem with the sealant, unlike the new ones.
By the way, on 6.2 tahoe k2 I drove 160 thousand km on 0w20 oil, without any problems))
Vlad, not sure what you mean by "the oil is left the same 0w20" but there is data backing up the breakdown of 0w20 by a poster here. After 3k miles, it barely held the viscosity of 20. Secondly, we've had members here who have lost multiple 6.2 engines in the same vehicle. Within short spans of time. Regarding the oil pump, we're not saying that the oil pump had some sort of defect that caused the failure. We're saying it has a design flaw because of it being 2-stage(lo/hi pressure).

Lastly, what data do you have in Russia that backs up your claim that "after repair, these engines last for a long time". It's my understanding no GM vehicles equipped with 2021+ L87 engines were ever officially exported to Russia.
 

Doubeleive

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Vlad, not sure what you mean by "the oil is left the same 0w20" but there is data backing up the breakdown of 0w20 by a poster here. After 3k miles, it barely held the viscosity of 20. Secondly, we've had members here who have lost multiple 6.2 engines in the same vehicle. Within short spans of time. Regarding the oil pump, we're not saying that the oil pump had some sort of defect that caused the failure. We're saying it has a design flaw because of it being 2-stage(lo/hi pressure).

Lastly, what data do you have in Russia that backs up your claim that "after repair, these engines last for a long time". It's my understanding no GM vehicles equipped with 2021+ L87 engines were ever officially exported to Russia.
You can't seriously believe these vehicles could not make it to Russia :buttkick:
 

Vladimir2306

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Vlad, not sure what you mean by "the oil is left the same 0w20" but there is data backing up the breakdown of 0w20 by a poster here. After 3k miles, it barely held the viscosity of 20. Secondly, we've had members here who have lost multiple 6.2 engines in the same vehicle. Within short spans of time. Regarding the oil pump, we're not saying that the oil pump had some sort of defect that caused the failure. We're saying it has a design flaw because of it being 2-stage(lo/hi pressure).

Lastly, what data do you have in Russia that backs up your claim that "after repair, these engines last for a long time". It's my understanding no GM vehicles equipped with 2021+ L87 engines were ever officially exported to Russia.
I mean that after the engine is repaired, the oil viscosity does not change. They also remain at a viscosity of 0w20. As for the breakdown after replacing the engine. There is an important nuance here, and the United States does not repair the engine, in the United States you change it to a new one. And the new engine is just as problematic in terms of clearances as the previous one, broken. In Russia, there were L87s on the escalade. But unofficially, we have a lot of Yukons, like mine with the L87 engine, a Tahoe with the same engine and an escalade, there are also Sieros... So yes, we bring these cars from the USA without any problems, and we are happy to drive them))) so about replacing the engine as in the USA. The service in which I service my Yukon brought a new engine several times, and put it in the car right out of the box, and it broke down again, after 1000 km. Now they disassemble the new engine from the box, increase the clearances, then assemble and put it on the car, such engines have already traveled more than 100 thousand km after repair
 

DontTaseMeBro

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I mean that after the engine is repaired, the oil viscosity does not change. They also remain at a viscosity of 0w20. As for the breakdown after replacing the engine. There is an important nuance here, and the United States does not repair the engine, in the United States you change it to a new one. And the new engine is just as problematic in terms of clearances as the previous one, broken. In Russia, there were L87s on the escalade. But unofficially, we have a lot of Yukons, like mine with the L87 engine, a Tahoe with the same engine and an escalade, there are also Sieros... So yes, we bring these cars from the USA without any problems, and we are happy to drive them))) so about replacing the engine as in the USA. The service in which I service my Yukon brought a new engine several times, and put it in the car right out of the box, and it broke down again, after 1000 km. Now they disassemble the new engine from the box, increase the clearances, then assemble and put it on the car, such engines have already traveled more than 100 thousand km after repair
What clearances are increased exactly?
 

Doubeleive

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In general, they get there without any problems, I ordered Yukon for myself in the USA and the logistics company brought it to me in Russia))
they end up every where... north korea, wherever...... "officially" perhaps not, that doesn't stop anyone or anything.....
the only thing you really do not see rolling around the streets of the USA is military grade weapons. i.e. rpg's. missiles, etc
but if you have money anywhere else in the world then it's for sale lol
you could be a bug on a pigs ass in the Arabian desert and buy a missile...
 

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