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.