2021 Z71 Tahoe Engine Failure Tear Down 4k Miles

[Semper1833]

 

[02Lightning]

When you say complete engine failure what does that mean? Rod hanging out the side of the motor, and oil everywhere? Or not running smooth and in limp mode?

 

[Holy Roller]

Likely a bad valve spring. Once replaced, you’ll be as right as rain.

 

[Geotrash]

I'd be upset too, but I wouldn't conclude that you won't be able to trust the truck again after the repair.

 

[OR VietVet]

I already know you are going to say that until the engine is tore down you have no idea what is wrong and that is also why you should not say, "complete engine failure" without saying why you say that. What EXACTLY happened to make you use that statement? Your emotions are driving the narrative right now instead of thinking it all through. No matter what you are talking about, a new part can be bad, period. Like has been said, a broken valve spring or anything else could have let go causing your problem that you have not bothered to share any details about. By the way, GM's only obligation is spelled out in black and white. They need to first find the actual problem and then tell you what they are going to do. They are also not gonna rebuild it, as you say. If it needs the valve spring or something simple, they will do that. If it needs the engine they will bolt in a new engine.

Welcome to the forum from Oregon and take a deep breath and tell us later what they find.

 

[dnt1010]

Buddy of mine bought a 2021 Sierra AT4 with the 6.2, it had a valve spring failure at around 6000 miles. GM apparently had a supplier that had a rash of bad valve springs for the 6.2 engines. I am not sure if it affected the 5.3 or not? Anyway the dealer replaced all valve springs in his 6.2 (after a about a week delay due to BACKORDERED VALVE SPRINGS which tells us that there really is an issue Haha).
He seems perfectly happy with his new truck now. Just the luck of the draw I guess.
If you are really not going to trust the vehicle maybe you can work a deal for a little bit out of pocket and get into a new one with zero miles and try it again.

 

[Fireman591]

Sorry to hear this . We just drove ours down to Orlando from Michigan. So far so good with about 3400 miles on it. I hope it holds together on the way home. At least it got us down here and did not ruin our trip. My engine was built in the window with the bad valve springs so pending on our settlement with our current litigation from a prior break down I will most likely replace all 16 valve springs if we decide to keep it if GM is not forced to buy it back. Still can't believe there is not a recall on this yet but hey at least that recall on the DRL bulb output color has me feeling so much safer now vs loss of power due to engine failure from a known problem with bad bad springs.

 

[Kpwweb]

Is that a Z71? I thought all Z71s had red tow hooks, black chrome trim, Z71 badges on the front fender just behind the hood, and Z71 running boards?

 

[Fireman591]

Buddy of mine bought a 2021 Sierra AT4 with the 6.2, it had a valve spring failure at around 6000 miles. GM apparently had a supplier that had a rash of bad valve springs for the 6.2 engines. I am not sure if it affected the 5.3 or not? Anyway the dealer replaced all valve springs in his 6.2 (after a about a week delay due to BACKORDERED VALVE SPRINGS which tells us that there really is an issue Haha).
He seems perfectly happy with his new truck now. Just the luck of the draw I guess.
If you are really not going to trust the vehicle maybe you can work a deal for a little bit out of pocket and get into a new one with zero miles and try it again.

Yes it was a bad batch that was sent to all 6.2 and 5.3 engines across all GM brands including the Corvette

 

[vcode]

So, don't know if this is related, but when Car and Driver did some skidpad testing on the 2021 triplets, not only were they shocked at the intrusive stability control, but they reported every one they tested smoked like crazy during their testing, something they have not seen in a really long time. They attributed it to oil control issues. Just repeating what they said, but I would find that very disturbing on a brand new vehicle.

 

[JasonHTX]

So, don't know if this is related, but when Car and Driver did some skidpad testing on the 2021 triplets, not only were they shocked at the intrusive stability control, but they reported every one they tested smoked like crazy during their testing, something they have not seen in a really long time. They attributed it to oil control issues. Just repeating what they said, but I would find that very disturbing on a brand new vehicle.

I assume you're referring to this ...

https://www.caranddriver.com/features/a34900893/2020-winners-and-losers-testing-edition/

It's the first negative thing I have read about the engines outside of the valve springs.

 

[Fireman591]

So, don't know if this is related, but when Car and Driver did some skidpad testing on the 2021 triplets, not only were they shocked at the intrusive stability control, but they reported every one they tested smoked like crazy during their testing, something they have not seen in a really long time. They attributed it to oil control issues. Just repeating what they said, but I would find that very disturbing on a brand new vehicle.

Hard to believe considering the 5.3 takes 8 quarts of oil

 

[vcode]

I assume you're referring to this ...

https://www.caranddriver.com/features/a34900893/2020-winners-and-losers-testing-edition/

It's the first negative thing I have read about the engines outside of the valve springs.

Yep, that is what I read. . 4g's is WW2 Jeep territory. Makes you wonder if you would have an issue off-roading if you veer to far from horizontal?