Main Bearing Failure with 6.2L at 3,200 miles

[Marky Dissod]

The GM TSB specifically tells the technician to take off the oil filter and look inside for metallic flakes.
No oil analysis necessary.

So the GM tech is going to 'visually' inspect for metallic flakes?
How much you wanna bet they're going to assign techs with bad vision specifically in terms of examining for ultrafine metallic particles?

 

[StephenPT]

So the GM tech is going to 'visually' inspect for metallic flakes?
How much you wanna bet they're going to assign techs with bad vision specifically in terms of examining for ultrafine metallic particles?

We're talking about spun main bearings here. This isn't an issue a dealer can say "can't replicate the customer complaint." The engine is either locked up or sounds like it's about to be - visual inspection of the oil filter is all that's needed to open the warranty claim through GM and get a new crate motor ordered.

 

[Dilligaf34]

Talked to a friend that is a tech at a local dealership, sounds like this problem is getting worse. The parts that are needed to do the engine replacement are going on back order, motor, radiator, gaskets, o-rings.

 

[Geotrash]

Talked to a friend that is a tech at a local dealership, sounds like this problem is getting worse. The parts that are needed to do the engine replacement are going on back order, motor, radiator, gaskets, o-rings.

The interesting thing about these (to me, at least) is that many of them are making it to 30, 40, 50K before spinning a bearing. Normally, defective bottom end parts will trigger a mechanical failure in the first few thousand miles. In this case, GM likely has no way to know how many of these are doomed until their red-faced owners come storming through their doors.

 

[Marky Dissod]

The interesting thing about these (to me, at least) is that many of them are making it to 30, 40, 50K before spinning a bearing.
Normally, defective bottom end parts will trigger a mechanical failure in the first few thousand miles.

Well, obviously, these are also defective
(even if GM would love to increase the number of engines that fail at approx 180,000 miles).

My suspicion is faulty metallurgy.

 

[Geotrash]

Well, obviously, these are also defective
(even if GM would love to increase the number of engines that fail at approx 180,000 miles).

My suspicion is faulty metallurgy.

Yes, they're absolutely defective. I only meant that it makes it even more unnerving to not know if/when it's going to grenade. And I suspect you're right about the metallurgy.

 

[Marky Dissod]

Since accountability at GM is (at least initially) NOT an immediate priority, it'll be RELATIVELY easy for prospective customers to figure out which vehicles to avoid buying after a short while.
Reminded of a scene in
Fight Club
where 'Tyler Durden' explains his job as a 'recall coordinator', whose job it was to apply
The Formula (should we initiate a recall?):
"Take
the number of vehicles in the field - A
multiply by
the probable rate of failure - B
then multiply (A*B) by
the average out-of-court settlement - C
(A*B)*C = X
"If 'X' is less than the cost of a recall,
WE DON'T DO ONE." - Tyler Durden

 

[JasonGMC]

I also joined the forum as my 2023 GMC AT4 with 6.2 spun the bearings and the engine seized with 11,000 miles on March 11, we were about 110 miles from home. It was towed 20 miles to a larger GMC dealer. The dealer called the next day and notified me the seized engine due to a spun bearing. The engine, radiator, 400amp fuse block, oil cooler lines along with many other parts were replaced. The engine seized at 3:30 on a Monday and the dealer called Friday morning and said it was done and ready to be picked up. Every tank of fuel since new was 91 octane or better and the oil had been changed twice. I love the 6.2 10 speed platform. I traded my 2017 GMC Duramax for a 2019 Silverado with the 6.2 and traded again for a 2021 Silverado 6.2 and now this AT4 6.2. I put on 20k miles per year with 10k pulling my walleye boat and have never had a problem until now.

 

[KMeloney]

If there were to be a TSB with measures to avoid this situation, what would it look like? What would need to be replaced to avoid these seizures?

 

[WalleyeMikeIII]

If there were to be a TSB with measures to avoid this situation, what would it look like? What would need to be replaced to avoid these seizures?

I don't think the general public knows just yet...

There could be several causes, and we don't yet know that the cause is, for the rod bearings, could be:
Oil Pump
Bad Bearing metallurgy
Bad machining on crank shaft
Clogged Oil Passages
Bad Bearing Manufacturing tolerance
Bad Rod Manufacturing tolerance
Bad Crank Manufacturing tolerance
Foreign Material
Bad Oil
etc...

For Main Bearings, causes could be different yet, but seems like the bulk of fails we are reading about are rod bearings, not main bearings.

Here is an interesting article on rod bearing fails.

https://www.kingbearings.com/wp-content/uploads/2014/10/Engine-bearing-failures-and-how-to-avoid-them1.pdf