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

[Roadglide16]

Will the same thing happen potentially to the 2025 models? Or, is it the same engine?

 

[malba2366]

“I don't think they will be able to get away with that. Random catastrophic engine failures become a safety issue. Look at the recent large recalls Toyota and Honda have had to do for engine issues.”

Briefly for my education, what did they do? Buy back, replace or new engines?

Toyota is replacing the engines in 100,000 of the trucks with the V6 engines that were prone to catastrophic failure. Not sure about the details of the Honda recall yet.

 

[jfoj]

I think the unfortunate situaiton is there appears to be at least 3 specific failure modes with the 5.3l and 6.2l and it is unclear if they are related in any way.

Lifter failures, often causing roller wearing, bent pushrods, twisted lifters, failure to pump back up.

Bearing failures, either main and/or rod, some may be due to the oversize lifter bores with oil starvation to the main and rod bearings, others may be due to bearing fit and/or bearing quality issues. Unclear how many of these may have been towing related.

Thrust bearing failures. Unclear if this is an oiling issue or build spec or bearing quality. Unclear how many of these may have been towing related.

All of the above could also be caused by oil pressure issues either due to the oil pump or low engine oil level. Is the 2 stage oil pump contributing to all of these problems? Fuel dilution could also be a contributing factor as well.

It would be great if the root cause(s) could be determined. Most of these failures appear to be under warranty so few 3rd parties have been able to review the damage. GM may know or hopefully knows what is going on. Either these are all related or they may be different failure modes. Asssume if GM knows what is going on they are not going to step up unless their hand is forced to take ownership and state VIN's that could be impacted.

It is really hard to be an "informed" and technically proficient owner to watch on the sidelines and hear about all of these failures. Is it really 1% or less, or are we are playing Russian Roulette with much higher percentages?

I am trying to do everything in my wheel house to hopefully eliminate these problems or reduce the chance of them occurring. This includes short Oil Change Intervals with oil analysis, magnetic oil drain plug, magnets on the oil filter which I cut open and check at each oil change, catch can and checking the oil every fill up or every other fill up. And running Preminum fuel at all times to hopefully combate Low Speed Pre-Ignition (LSPI) that could be ******* the rod bearings. Also running a DFM disable and Auto Stop/Start disabler. DMF disable is to hopefully reduce the busyness of lifters/cyliners being disabled to help eliminate some of the potential problems.

Also wondering if the 6.2l may be more prone to rod bearing issue due to the high torque at lower RPMs, some what a lugging with the 10 speed transmission?? This may be putting more stress on the rod bearings and oiling system, but who knows.

Is the 0W20 oil part of the problem? I think it is. The only reason they are using 0W20 is due to government CAFE requirments.

This is about all I can do to protect the engine and try and track if there are problems brewing. If I have an engine failure, I can pretty much eliminate anything I have control over. I hope I can have a long engine lifespan without issues, but we will see.

The safety issues of the engine randomly quiting, oil possibly being dump on the road and getting on the tires and the transmission possibly going into Park once the vehicle stops and not being able to move the vehicle without towing are all reasons to be concerned.

I really hope these failures are a low precentage and that there may be a bit more transparency about what is going on. GM went from bulletproof engines 20 years ago to these disasters due to all the government CAFE requirments.

 

[Roadglide16]

Yes, I believe this is a safety issue. My son and his family were driving their 2022 Tahoe, 6.2 and experienced a catastrophic engine failure on the interstate at 70 mph. They were barely able to coast across three lanes of high-speed traffic to the shoulder. At that time the vehicle only had 40,000 miles on it and required a full engine replacement.

 

[RG23RST]

I think the unfortunate situaiton is there appears to be at least 3 specific failure modes with the 5.3l and 6.2l and it is unclear if they are related in any way.

Lifter failures, often causing roller wearing, bent pushrods, twisted lifters, failure to pump back up.

Bearing failures, either main and/or rod, some may be due to the oversize lifter bores with oil starvation to the main and rod bearings, others may be due to bearing fit and/or bearing quality issues. Unclear how many of these may have been towing related.

Thrust bearing failures. Unclear if this is an oiling issue or build spec or bearing quality. Unclear how many of these may have been towing related.

All of the above could also be caused by oil pressure issues either due to the oil pump or low engine oil level. Is the 2 stage oil pump contributing to all of these problems? Fuel dilution could also be a contributing factor as well.

It would be great if the root cause(s) could be determined. Most of these failures appear to be under warranty so few 3rd parties have been able to review the damage. GM may know or hopefully knows what is going on. Either these are all related or they may be different failure modes. Asssume if GM knows what is going on they are not going to step up unless their hand is forced to take ownership and state VIN's that could be impacted.

It is really hard to be an "informed" and technically proficient owner to watch on the sidelines and hear about all of these failures. Is it really 1% or less, or are we are playing Russian Roulette with much higher percentages?

I am trying to do everything in my wheel house to hopefully eliminate these problems or reduce the chance of them occurring. This includes short Oil Change Intervals with oil analysis, magnetic oil drain plug, magnets on the oil filter which I cut open and check at each oil change, catch can and checking the oil every fill up or every other fill up. And running Preminum fuel at all times to hopefully combate Low Speed Pre-Ignition (LSPI) that could be ******* the rod bearings. Also running a DFM disable and Auto Stop/Start disabler. DMF disable is to hopefully reduce the busyness of lifters/cyliners being disabled to help eliminate some of the potential problems.

Also wondering if the 6.2l may be more prone to rod bearing issue due to the high torque at lower RPMs, some what a lugging with the 10 speed transmission?? This may be putting more stress on the rod bearings and oiling system, but who knows.

Is the 0W20 oil part of the problem? I think it is. The only reason they are using 0W20 is due to government CAFE requirments.

This is about all I can do to protect the engine and try and track if there are problems brewing. If I have an engine failure, I can pretty much eliminate anything I have control over. I hope I can have a long engine lifespan without issues, but we will see.

The safety issues of the engine randomly quiting, oil possibly being dump on the road and getting on the tires and the transmission possibly going into Park once the vehicle stops and not being able to move the vehicle without towing are all reasons to be concerned.

I really hope these failures are a low precentage and that there may be a bit more transparency about what is going on. GM went from bulletproof engines 20 years ago to these disasters due to all the government CAFE requirments.

I've not seen or heard of a 5.3 with bottom end issues. Not saying it hasn't happened anywhere but that's a 6.2 issue mainly. The oversize lifter bore issue was a small batch IIRC and mainly would have caused lifter deactivation issues with hot, thin oil unable to maintain the required 22psi to the locking pins. If that pressure or volume isn't maintained the lifter will attempt to re-lock itself no matter where it is on the cam, causing bent push rods, lifters ratcheted down in the "safety" position and so on.

Unfortunately I just don't see anything coming down the line for the AFM/DFM lifter "problem." Any hydraulic roller lifter can spit out the needle bearings and wreck the cam, or spin in the lifter tray and also wreck the cam. Cylinder deactivation being present or not doesn't affect that either way. DFM is just one more thing to maintain and most people just don't want to worry with it understandably. Even something like an intermittent ground fault from a strap losing continuity can cause the solenoids to act out of time and cause all sorts of issues. It does save a non-trivial amount of fuel if you drive it normally but is it worth it?

 

[PPV_2018]

Ya know, one has to wonder if a NHTSA mandated recall wouldn’t actually **benefit** gm, as opposed to class action lawsuits.. because for one if i understand correctly, if a recall is in effect then lawsuits of that subject cannot proceed in court, correct? Then also, I’m sure gm will try the obligatory C.Y.A. & minimize the numbers of failures and issues.

And could gm truly foot the bill for that many defective engines.. or will have another case of government motors bailout.

Even something like an intermittent ground fault from a strap losing continuity can cause the solenoids to act out of time and cause all sorts of issues.

Not to get off topic, but what exactly are you referring to that could cause the ground strap to lose continuity ?

 

[PPK_]

I get it.. oil pressure is low.. you are going to loose bearings further from the pump. My 2024 yukon has 1100 miles on it.. 5.3. I noticed on the first change.. a lot of metal material in the drain oil. I then took the filter apart to see.. what was in there. There is a lot on the filter.. what you see on the magnet is just a pass over a little bit. I wonder if they are doing something less in the engine build. Maybe just quality down to where the engines do not last? I can say.. it is a lot more metal than what my 2.7 had.. not really happy,at this point.

I think it is a good idea to dump the oil after a month or so.. when new.

 

[RG23RST]

Ya know, one has to wonder if a NHTSA mandated recall wouldn’t actually **benefit** gm, as opposed to class action lawsuits.. because for one if i understand correctly, if a recall is in effect then lawsuits of that subject cannot proceed in court, correct? Then also, I’m sure gm will try the obligatory C.Y.A. & minimize the numbers of failures and issues.

And could gm truly foot the bill for that many defective engines.. or will have another case of government motors bailout.


Not to get off topic, but what exactly are you referring to that could cause the ground strap to lose continuity ?

There are a couple of ground straps from the block to the chassis that love to rot away in areas that use road salt.

 

[RG23RST]

I get it.. oil pressure is low.. you are going to loose bearings further from the pump. My 2024 yukon has 1100 miles on it.. 5.3. I noticed on the first change.. a lot of metal material in the drain oil. I then took the filter apart to see.. what was in there. There is a lot on the filter.. what you see on the magnet is just a pass over a little bit. I wonder if they are doing something less in the engine build. Maybe just quality down to where the engines do not last? I can say.. it is a lot more metal than what my 2.7 had.. not really happy,at this point.

I think it is a good idea to dump the oil after a month or so.. when new.

The oil pressure these engines run at isn't an issue. The vane-type oil pumps in the L84/L87 are high volume even when the commanded PSI is on the lower side.

Somewhat off topic, you'd be shocked to see what shows up in the first oil change for any Toyota in the last decade plus. Both a previous 2018 Camry and brand new Grand Highlander we have now were absolutely full of metal when I dumped the oil early. Pretty much every model you'll find that observation (and panic) for those that DIY the first couple of oil changes. It doesn't take long for the components to wear into each other and they're fine for 200K miles on nothing but oil, filters and plugs.

 

[DontTaseMeBro]

Will the same thing happen potentially to the 2025 models? Or, is it the same engine?

Engine is the same. Hopefully GM wisely made the necessary changes going forward to avoid anymore failures.