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

[jfoj]

Not sure the oil pump is too small?? But I think it is a combination of factors. I am just starting to research the prior generation 6.2l L86 which is very similar, main difference is AFM vs DFM but there may be others, I never studied up on the L86 as I never owned one.

Seems that a few things are contributing.

1. 2 stage vane style oil pump. Maybe?? GM dropped the oil pressure on the low stage compared to the L86?? The 2 stage pump is likely for fuel economy reasons, but is not so good for long term reliability IHMO. Oil not only lubricates, but it also cools. Also if for some reason air is getting in the oil supply then this is not good either.

2. Low viscosity oil and Auto Stop/Start. You end up introducing more dry or partially dry engine starts based on a fuel saving feature. I would rather use more fuel and have the engine last!

3. The vane style oil pumps seem to lose their prime quickly. Clearly overnight they will lose their prime, but what about during Auto Stop/Starting? With the lower viscosity oil, then the loss of prime will be quicker and more frequent than with a slightly higher viscosity oil. Will the oil pump eat itself sooner with 0W20 vs 5W30 when losing prime? Who knows.

4. Higher viscosity oil tends to drain back and out of bearing journals slower than lower viscosity oil. So there should be a slightly more protective oil film left in the oil pump and on the bearing journals when compared to 0W20.

Hell, maybe GM recall the 6.2l and reprograms the OLM/OCI and reprogram the ECU to only run the oil pump on the higher stage. I just do not see GM taking drastic action like Toyota and just replacing engines that have not failed, this is not in their playbook from my experience.

 

[kmcintosh]

Are there any known warranty issues if you go with the 5W30 oil? Instead of the manufactures recommendation?

 

[mountie]

Are there any known warranty issues if you go with the 5W30 oil? Instead of the manufactures recommendation?

Don't tell anyone at the dealer...... They won't know the difference. I doubt they will bother to check.

 

[jfoj]

First, is the dealer going to test the oil? No, they are going to pull the filter and drain the pan looking for the glitter and they will not even likely pull the oil pan with the track record of the 6.2l failures. Additionally with the track record of the 6.2l failures, there is no way they could claim a slightly higher viscosity oil could have lead to these failures. They could try, but I think at this point history is not on GM's side. The more I search and the more I read about all the 6.2l failures I am guessing they are into the 5000 range based on just the numbers I am finding an this is not all that have been reported.

Best thing you can do is document date, mileage and engine run hours for every oil change you perform. If you want to go above and beyond, obtain oil samples from either Blackstone Labs or Speed Diagnostics so you also have supporting information about how the oil condition was during changes. I would also log date, mileage and engine hours when oil was checked and if any oil was added between changes.

May want to consider a GM extended warranty (GMPP) to go beyond factory powertrain warranty coverage just so you have something to fall back on in case GM and/or the Class Action Lawsuits do nothing for you. Usually Class Action Lawsuits get the lawyers rich and will give you $500 your next GM purchase!

 

[jerry455]

I am using 0W30 Mobil 1 in my 6.2 with 81,000 miles.

 

[jfoj]

I am using 0W30 Mobil 1 in my 6.2 with 81,000 miles.

Good, better than 0W20.

So some questions:

What year vehicle?
Did you buy vehicle new?
Is this the original engine?
At what mileage did you start with 0W30?
How many miles do your change your oil or do you follow the OLM/OCI?
Any oil consumption between changes and how much?
How many hours are on the engine?
Do you use the Auto Stop/Start feature?
Is the Auto Stop/Start feature bypassed?
Do you have any sort of AFM/DFM disabler?

 

[Silverado4x4]

First, is the dealer going to test the oil? No, they are going to pull the filter and drain the pan looking for the glitter and they will not even likely pull the oil pan with the track record of the 6.2l failures. Additionally with the track record of the 6.2l failures, there is no way they could claim a slightly higher viscosity oil could have lead to these failures. They could try, but I think at this point history is not on GM's side. The more I search and the more I read about all the 6.2l failures I am guessing they are into the 5000 range based on just the numbers I am finding an this is not all that have been reported.

Best thing you can do is document date, mileage and engine run hours for every oil change you perform. If you want to go above and beyond, obtain oil samples from either Blackstone Labs or Speed Diagnostics so you also have supporting information about how the oil condition was during changes. I would also log date, mileage and engine hours when oil was checked and if any oil was added between changes.

May want to consider a GM extended warranty (GMPP) to go beyond factory powertrain warranty coverage just so you have something to fall back on in case GM and/or the Class Action Lawsuits do nothing for you. Usually Class Action Lawsuits get the lawyers rich and will give you $500 your next GM purchase!

You can log all you want if do your own oil changes your going to need a recipe also to prove your oil changes and the recipe will show what type of weight oil you purchased.

 

[jfoj]

I will worry about that when the time comes, I will also have oil analysis for every oil change and I will also have a separate ziplock bag for the oil filter that is removed at each oil change and cut open stored in a ziplock bag with date, mileage and engine hours written on the bag.

If these motors were not timebombs, I could see it being a fight, but there are easily a few a week that are mentioned over a few forums, Reddit and social media. The 2024's are also having problems as well as the hand built supercharged 6.2l engines in the Cadillac Type V, I do not factor in the Corvettes too much due to the dry sump system they are running.

I just performed my 2nd oil and filter change at 3484 miles with 76 hours on the engine for an oil change mileage of 2940 miles since the first oil change. The OLM was at 53% which I did not reset at the first oil change, so somewhere between 3000-4000 miles I will expect the OLM to be around 50% depending on driving conditions. I reset the OLM today when I performed this oil change. I am planning to perform oil changes about every 3000-3500 miles or when the OLM gets close to 50%. No need to try and find out how long I can stretch an oil change out.

I have a J&L catch can on the truck as well. I checked and emptied it today, it was about 1/2 full of oil and had probably a bit over 3/16" water below the oil. No oil consumption for this distance that I could perceive.

Will see what the oil analysis indicates and plan on around 3500 miles for the next oil change.

Will also benchmark my oil pressure after I get about 100 miles on the new oil using an advanced scan tool that can read the oil pressure from the ECU rather than trying to figure out the oil pressure from looking at the dash gauge. This will be used to compare to future oil changes as well.

Not much more a person can do to try and keep one of these engines running. Between a short OCI, Filter Mags on the oil filter, magnetic drain plug and a catch can, checking the oil ever fill up or every other fill up, anything else is on GM.

 

[RG23RST]

Changing the oil more often or to a different viscosity won't help you. The issue is with the bearings in the bottom end of the motor. Again, same design oiling system exists in the 5.3 and 6.6 and neither have this issue.

 

[RG23RST]

Basically,, the oil pump is too small. not great news... especially at a lower rpm. bummer.

The vane-style pumps fail to high pressure/high(er) volume if the pump control solenoid ever fails. They also are less prone to aeration issues and deliver more consistent performance than the older gerotor style. Transmissions have used this style of pump for decades.