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

[KMeloney]

And they don’t magically happen at the same spot every time or nearly every time.

What is the "same spot nearly every time" you're referring to?

 

[jfoj]

Unsure if the 2025 models will be "fixed"???

There were some suspect bearing issues, but this should have only been around 2021-2022 MY??

Then there was the "Oversize Lifter Bores". There is supposed to be a VIN range on these but it has never been released publically that I am aware of and GM was "supposed" to send letters to customers that may have been impacted. I recall this was 2022-2023 MY? If a dealer has a specific VIN in for other repairs, it was implied that the dealer should hold the vehicle and replace the engine. I have not heard anyone say they have been in any of these situations.

There have been camshaft and lifter problems, have not heard much about this isssue as of late. Maybe the engines are failing before the lifters and camshafts have problems??? Maybe the lifter and camshaft issue has been resolved?

Have seen a small number of engines where the piston wrist pin retainer was missing or not properly seated, piston pin walking, causing the piston to wedge in cyliner and in this case usually a connecting rod breaks. Again, not sure this is a large scale issue.

Unfortunately we have even seen newer build date replacement engines fail shortly after installed or within 6000-12000 miles. Unsure why this has happened.

There are a number of other suspected issues, GM has not mentioned these, but some folks are looking into some areas of concern. Unclear if these issue are confirmed contributors, but there could be some action owners could try and take to counter some of these concerns.

Bottom line, all you can do as an owner at this point is change your oil before or when the OLM hits 25%, do not warm up the engine without driving the vehicle as this leads to excessive fuel dilution in the engine oil, check the engine oil every other fill up, run Preminum fuel, and strongly consider something other than 0W20 engine oil, either 5W30 or 0W40, especially if you tow with your rig.

 

[Stbentoak]

What's the "evidence" here? It's been suggested (by way of that customer satisfaction letter that no one actually received) that GM thinks it knows the general range of engines that these parts were installed in.

I don't pretend to have THE answer(s) here. I'm not even playing devil's advocate or anything. This was just my understanding of the situation to date.

The broad evidence is this..... It's been going on since the 21-model year. Various engine failures that result in tear downs to replacements. Both V-8's. 5.3's to a lesser extent.

Four years. Still continuing.

It's pretty likely that lifters are still being replaced, it's just that those people aren't on here. And most of the people on here that have had problems are probably on their second set of lifters. Many of the current engine replacement victims aren't on here. My dealer always has at least three plus units sitting in the holding pen waiting on engines.
I really don't know what's wrong with them..... it could be a collection of issues from bad parts at certain times, to bad machining at other times, to and including complete design flaws that they are not willing to own up to. All I know is that it is very erosive of customer satisfaction, loyalty and product confidence to lose engines. Word gets around.

Need a new water pump or alternator? I can live with that. Need a new engine along with others behind me at the dealership? That's a deal breaker for future purchases.

 

[blanchard7684]

What is the "same spot nearly every time" you're referring to?

The same bearings are the culprit.

 

[jfoj]

Seems the front main bearing and often the #1 and #2 rod bearings are a common failure, then the other seems to be the crankshaft thrust bearing on main bearing #3. There are other failures but these seem to be a bit more common from what I have found. Have been searching quite about about these failures and at least when there is supporting info this is what I am finding.

 

[KMeloney]

The same bearings are the culprit.

That seems to point to bad bearings, right? (That’s what my local dealer tech thinks anyway.)

 

[jfoj]

There is more to the story. Understand that the front main bearing is the next to LAST bearing in the oiling path and #1 rod bearing is the last as it is oiled from the front crank bearing. If the #1 rod bearing gets hot, it can then transfer heat to the #2 bearing. The best bearings in these positions will not survive if there is a lack of lubrication. There are other contributing factors to what is going on.

 

[KMeloney]

There is more to the story. Understand that the front main bearing is the next to LAST bearing in the oiling path and #1 rod bearing is the last as it is oiled from the front crank bearing. If the #1 rod bearing gets hot, it can then transfer heat to the #2 bearing. The best bearings in these positions will not survive if there is a lack of lubrication. There are other contributing factors to what is going on.

I believe it. I’m not suggesting that it’s only a supplied-parts issue— just that that’s what I’ve heard and read about being a (if not the) prime factor.

How new is this particular engine’s design? Is it new to the ‘21 models? If it’s much older than that, then has the 6.2 been failing like this for years and years (more than just the last four)? If it’s only just begun to fail with the ‘21 models, and the design changed starting for ‘21, then I could certainly understand it being a design issue. But then that would also suggest that EVERY 6.2 (since the design change, anyway) WILL fail… Right?

 

[RG23RST]

Unsure if the 2025 models will be "fixed"???

There were some suspect bearing issues, but this should have only been around 2021-2022 MY??

Then there was the "Oversize Lifter Bores". There is supposed to be a VIN range on these but it has never been released publically that I am aware of and GM was "supposed" to send letters to customers that may have been impacted. I recall this was 2022-2023 MY? If a dealer has a specific VIN in for other repairs, it was implied that the dealer should hold the vehicle and replace the engine. I have not heard anyone say they have been in any of these situations.

There have been camshaft and lifter problems, have not heard much about this isssue as of late. Maybe the engines are failing before the lifters and camshafts have problems??? Maybe the lifter and camshaft issue has been resolved?

Have seen a small number of engines where the piston wrist pin retainer was missing or not properly seated, piston pin walking, causing the piston to wedge in cyliner and in this case usually a connecting rod breaks. Again, not sure this is a large scale issue.

Unfortunately we have even seen newer build date replacement engines fail shortly after installed or within 6000-12000 miles. Unsure why this has happened.

There are a number of other suspected issues, GM has not mentioned these, but some folks are looking into some areas of concern. Unclear if these issue are confirmed contributors, but there could be some action owners could try and take to counter some of these concerns.

Bottom line, all you can do as an owner at this point is change your oil before or when the OLM hits 25%, do not warm up the engine without driving the vehicle as this leads to excessive fuel dilution in the engine oil, check the engine oil every other fill up, run Preminum fuel, and strongly consider something other than 0W20 engine oil, either 5W30 or 0W40, especially if you tow with your rig.

Lifter replacements slowed down for us quite a lot once the bad batch of 2021 was worked through. I've seen a couple here and there but nothing DFM related. It's usually the roller bearings in the lifter that failed. Lifter problems caused by the de-act mechanism have never been much of an issue as long as I've been working on them even back to the AFM engines. There were always other issues at play (plugged LOMA, ground straps rotting off, etc) the caused the lifters to be found in a "locked down" state that happens to prevent engine damage if there's a mis-timed activation or de-activation.

 

[RG23RST]

I believe it. I’m not suggesting that it’s only a supplied-parts issue— just that that’s what I’ve heard and read about being a (if not the) prime factor.

How new is this particular engine’s design? Is it new to the ‘21 models? If it’s much older than that, then has the 6.2 been failing like this for years and years (more than just the last four)? If it’s only just begun to fail with the ‘21 models, and the design changed starting for ‘21, then I could certainly understand it being a design issue. But then that would also suggest that EVERY 6.2 (since the design change, anyway) WILL fail… Right?

Other than some superseding component part numbers the engine hasn't changed since it rolled out in the summer/fall of 2018. Lifter p/n changed in MY22 but unsure what actually changed. They're listed as backward compatible to all DFM and AFM engines now.

Completely anecdotal evidence I've seen more transmission issues in MY19-MY20 trucks/SUVs with the 10L than engine issues. The gen1 10L had a bad pump idler design that was fixed in later years. I don't recall seeing an L87 fail in the "locked up and won't budge" way from either of those years. Doesn't mean it hasn't happened I just personally haven't seen it in our small dealership. Like a lot of things many of these issues started during/after covid.