2nd time Lifter Failure... 2021 Yukon AT4

[Quark]

GM is leaving buyers hanging on this one. They are stuck with a bad design and possibly going under and their only consolation is that the competition is in the same boat. Buyer beware.

 

[Usdmskyline20]

I'm now convinced it was not a bad batch but just a design flaw. My Yukon was built in May; lifter failure at 5000 miles. Dealer replaced both banks, all 16 lifters. 500 miles later, lifter failure AGAIN. The 75k pile of sh*t is being towed to dealer again tomorrow. If you are on the fence about getting a 21, just go visit the service bay at your local GMC dealer. Mine had 7 Yukons/Tahoe's currently in for lifter failure. It's definitely not just a small vocal few having this issue.

Plenty of threads on this, but I wanted to let people know, just because you had both banks replaced with the supposed *fixed* batch of lifters, you aren't in the clear.
So frustrating, as this was the perfect vehicle for my family. Now I'm trying to find a Jeep Dealer with an allocation for a Wagoneer.

Did yours come equipped with Afm?

 

[Xsbank]

Covid cars. I just took a beating getting out of a 2021 Ford Exploder ST that was a nightmare and no parts for months. Total POS. I traded it on a 2020 Denali demo and what a concept, everything works! For continued happiness, buy a BC (before Covid) car, when everything was “normal” in our factories.

 

[Fireman591]

It is a design flaw that has doubled with the DFM system. This guy explains it well and our dealers up here are seeing wear marks near the base of the push rods so harmonics might be a big chunk of this puzzle.

 

[mikeyss]

Covid cars. I just took a beating getting out of a 2021 Ford Exploder ST that was a nightmare and no parts for months. Total POS. I traded it on a 2020 Denali demo and what a concept, everything works! For continued happiness, buy a BC (before Covid) car, when everything was “normal” in our factories.

I'm curious, what all was wrong with your Explorer ST?

 

[Hrocks]

I follow a good number of mechanics on tiktok. Most of them are very reputable and work for reputable deals. For GM, The 20's and 21's are the worst years for lifter failures and DOD issues. Toyota 4Runners - avoid. They are dropping cranks between 5k & 10kon the 20's and 21s. FCA (dodge/fiat/jeep/etc) have spare transmissions cause the 8 speeds are going to explode...and they are 3-6 months backordered, worse than the GM lifters and 6L80 transmission parts. Ford has electrical and module problems out the wazu. Honda's, Nissan, and a couple others all have module issues.

It doesn't matter the brand you buy. Anything in the 20-21 years is in for issues. And they expect a crap ton more because the cars that have been sitting waiting for the modules with the chip backorder issue, are going to have other issues because the cars have been sitting for a year or more without running

I would take exception with the "Anything in the 20-21 years is in for issues". (except for all GM 5.3 and 6.2 motors ) GM is notorious for developing new platforms on the backs of their early adopter customers, which the past couple of full sized SUV's, has lasted for at least the first TWO years. It's very unfortunate and totally avoidable with adequate engineering development. I had enough of being a guinea pig when I had an '07 Escalade...I lived at the dealer. Cadillac was NO help. In any case, I have moved on and own two BOF Lexus SUV's and my great 2010 Tahoe LTZ. IMO, the last and best full size SUV platform was the 2013 of the GMT 900. It took GM until the last two years of the GMT K2XX to get them right. They have apparently taken the same approach on GMT T1XX...unexcuseble

 

[jayoco]

I'm now convinced it was not a bad batch but just a design flaw. My Yukon was built in May; lifter failure at 5000 miles. Dealer replaced both banks, all 16 lifters. 500 miles later, lifter failure AGAIN. The 75k pile of sh*t is being towed to dealer again tomorrow. If you are on the fence about getting a 21, just go visit the service bay at your local GMC dealer. Mine had 7 Yukons/Tahoe's currently in for lifter failure. It's definitely not just a small vocal few having this issue.

Plenty of threads on this, but I wanted to let people know, just because you had both banks replaced with the supposed *fixed* batch of lifters, you aren't in the clear.
So frustrating, as this was the perfect vehicle for my family. Now I'm trying to find a Jeep Dealer with an allocation for a Wagoneer.

Fill out your information: https://www.classaction.org/gm-lifter-problems-lawsuit

 

[RobFog]

Oh man that’s terrible to hear. Your build date is 2020 or 21? Seems like high mileage in less than 2 months for a 21 and already on the 2nd failure good lord…

I believe he said 75k$

 

[RobFog]

I believe he said 75k$

We had 2 lifters go out in July at 3k miles. They replaced all 16. Now 6 months later we are having the same issue.

 

[wsteele]

It is a design flaw that has doubled with the DFM system. This guy explains it well and our dealers up here are seeing wear marks near the base of the push rods so harmonics might be a big chunk of this puzzle.

The pushrods bending has nothing to do with harmonics or design flaws. The push rods can be bent because of the failure mode of these particular lifters (some of the time). Historically, when an AFM lifter fails, it fails to lock back into normal lifter mode. The top half of the lifter moves up and down as the cam lobe on that valve moves up and down as it rotates. This mode allows the pushrod to stay in the cups of the lifter and rocker.

In the 2021 MY lifter failures, the failure mode of the lifter is the lock pin spring breaks and the upper half of the lifter can jam in the down position. In this failure mode, the upper half stops moving up and down in time with the cam lobe and hence, when the cam lobe moves off the "valve actuated" position, the upward pressure on the push rod that keeps it in position of the cups of the lifter and rocker that it normally rides in is removed and the pushrod can fall out of the cup in the rocker and potentially also the lifter. With the next revolution of the engine, the cam lobe comes around and pushes the lifter up, the push rod can be misaligned outside the two cups and jammed against an immovable object (or at least a portion of the rocker arm with less movability) and immediately bent.

When the DFM lifter fails and the failure mode is the lifter just keeps going up and down in cylinder deactivation mode (never locking back into normal fire mode, but not jammed down), even when the engine is commanded to be in V8 mode, you get the hard miss, the CEL, the Christmas tree of misleading lights and messages, a failed lifter, but no bent pushrod.

 

[wsteele]

I'm now convinced it was not a bad batch but just a design flaw. My Yukon was built in May; lifter failure at 5000 miles. Dealer replaced both banks, all 16 lifters. 500 miles later, lifter failure AGAIN. The 75k pile of sh*t is being towed to dealer again tomorrow. If you are on the fence about getting a 21, just go visit the service bay at your local GMC dealer. Mine had 7 Yukons/Tahoe's currently in for lifter failure. It's definitely not just a small vocal few having this issue.

Plenty of threads on this, but I wanted to let people know, just because you had both banks replaced with the supposed *fixed* batch of lifters, you aren't in the clear.
So frustrating, as this was the perfect vehicle for my family. Now I'm trying to find a Jeep Dealer with an allocation for a Wagoneer.

When your truck was built isn't the governing factor. When your engine was built is the important factor. Many trucks have sat uncompleted waiting for various parts, such that the normal "few weeks" between engine completion and truck completion doesn't always apply to these trucks. Many have sat a long time waiting in various stages of completion. The build date, along with the factory the engine was built in, the shift it was built on and its sequence number is on a sticker on the back of the drivers cylinder head.

Edit: I guess I am just talking to myself, seems the OP registered, posts his troubles, answered Geotrash's question about being a new poster, then never came back...

I think I kinda know how a trout feels as he is rising for the bait.

 

[RobFog]

This is what happened to our 2021 Z71 this time around. 7/21 2 lifters went out. They replaced all lifters. This past Saturday another lifter went out and it damaged the cam shaft too. Definitely a design flaw in the engine.

 

[wsteele]

This is what happened to our 2021 Z71 this time around. 7/21 2 lifters went out. They replaced all lifters. This past Saturday another lifter went out and it damaged the cam shaft too. Definitely a design flaw in the engine.

My guy at our local dealer doesn't see it that way. I posted this on the other thread you just posted on, but if you could post the name and location of your dealer, I would love to have my guy give them a call for his own edification. Right now, he is convinced, once you replace all 16, the problem is resolved.

 

[Taos_AT4]

Morning Folks,

First post here, which is unfortunate because I really like our AT4. Two days ago, my wife called me about the car suddenly shaking and several warning lights popping up. After a little research, I think we are experiencing the same issue. We have a 2021 AT4 with the 5.3L. 17,100 miles. We don't have any of the serious knocking yet, which is why I'm having it towed instead of driving the 5 miles to the dealership. We purchased this brand new in April and love it, but this is frustrating. After reading several forums, technical service bulletins, and now a class action lawsuit, it seems like GM knows about the issue but is playing the odds.

Can't get mine into my local dealership to be diagnosed for two weeks, but I'm willing to bet this is the issue. I've heard about the Chevy Shake, and ours definitely has it. Maybe more of a GMC Jiggle..... I'll keep you updated on the progress. My ideal solution would be for them to replace the lifters on both banks and extend our warranty. We'll see what happens.

 

[wsteele]

Morning Folks,

First post here, which is unfortunate because I really like our AT4. Two days ago, my wife called me about the car suddenly shaking and several warning lights popping up. After a little research, I think we are experiencing the same issue. We have a 2021 AT4 with the 5.3L. 17,100 miles. We don't have any of the serious knocking yet, which is why I'm having it towed instead of driving the 5 miles to the dealership. We purchased this brand new in April and love it, but this is frustrating. After reading several forums, technical service bulletins, and now a class action lawsuit, it seems like GM knows about the issue but is playing the odds.

Can't get mine into my local dealership to be diagnosed for two weeks, but I'm willing to bet this is the issue. I've heard about the Chevy Shake, and ours definitely has it. Maybe more of a GMC Jiggle..... I'll keep you updated on the progress. My ideal solution would be for them to replace the lifters on both banks and extend our warranty. We'll see what happens.

Two weeks to get them to look at it is terrible. I think I would complain to the GM Regional folks just about that alone. That is a terrible standard of customer service.

If you kept OnStar, you can call them and they may be able to read any codes that have been set. A P030X, with X being the cylinder that is missing will tell you a lot (It might have just set P0300 as well). If you don't have a P030X, you might have dodged a bullet on the lifter issue.

The bad news is with your mileage, I think GM's guidance is still to replace the lifters in the bank that has the collapsed/stuck DFM lifter. Definitely ask for a loaner and an extended 6yr/100K Powertrain warranty if it ends up being a bad DFM lifter and they replace only one bank.

 

[Taos_AT4]

Two weeks to get them to look at it is terrible. I think I would complain to the GM Regional folks just about that alone. That is a terrible standard of customer service.

If you kept OnStar, you can call them and they may be able to read any codes that have been set. A P030X, with X being the cylinder that is missing will tell you a lot (It might have just set P0300 as well). If you don't have a P030X, you might have dodged a bullet on the lifter issue.

The bad news is with your mileage, I think GM's guidance is still to replace the lifters in the bank that has the collapsed/stuck DFM lifter. Definitely ask for a loaner and an extended 6yr/100K Powertrain warranty if it ends up being a bad DFM lifter and they replace only one bank.

Thanks for the advice. The Chevy dealer here in Taos is pretty small, so I thought the lead time was reasonable. Initially after hearing that lead time my plan was to drive the 60 miles to Santa Fe, but after reading about the issues, I decided I would have it towed to the dealership here in Taos. After calling them to schedule it she called me back to say her tech could look at it today if we can get it there in the next couple of hours. I mentioned the issues, warnings, and what I thought the issue was. When she called me back the tech thought it sounded "Electrical"..... So maybe I do want it towed to the GMC Dealership in Santa Fe...... On the line with Roadside Assistance to get it towed there now. We'll see what they say.

 

[Micahsd]

Morning Folks,

First post here, which is unfortunate because I really like our AT4. Two days ago, my wife called me about the car suddenly shaking and several warning lights popping up. After a little research, I think we are experiencing the same issue. We have a 2021 AT4 with the 5.3L. 17,100 miles. We don't have any of the serious knocking yet, which is why I'm having it towed instead of driving the 5 miles to the dealership. We purchased this brand new in April and love it, but this is frustrating. After reading several forums, technical service bulletins, and now a class action lawsuit, it seems like GM knows about the issue but is playing the odds.

Can't get mine into my local dealership to be diagnosed for two weeks, but I'm willing to bet this is the issue. I've heard about the Chevy Shake, and ours definitely has it. Maybe more of a GMC Jiggle..... I'll keep you updated on the progress. My ideal solution would be for them to replace the lifters on both banks and extend our warranty. We'll see what happens.

Do you know when the build date is on yours? It can be found on a label inside the drivers side door jam.

I bought mine in April too and the build date was March (dealer could look it up to find it was Mar 19th) although the date code on the motor shows Feb 11th which makes mine in that range of bad lifters. So far I haven’t had an issue yet although only have 7,500 miles on it.

It’s unfortunate that you got hit with the lifter issue.

 

[Taos_AT4]

Do you know when the build date is on yours? It can be found on a label inside the drivers side door jam.

I bought mine in April too and the build date was March (dealer could look it up to find it was Mar 19th) although the date code on the motor shows Feb 11th which makes mine in that range of bad lifters. So far I haven’t had an issue yet although only have 7,500 miles on it.

It’s unfortunate that you got hit with the lifter issue.

I'll have to check next time I'm at the dealership. Called GM Roadside assistance and they towed it to the Chevy dealer here in Taos. They originally wanted to tow it to a GMC dealer in Santa Fe because the Chevy shop wasn't pulling up on their end. After providing the address they were able to confirm they were certified. I'll check back when it I get a chance.

Is the motor code also on the door or does the dealer need to look it up?

 

[Micahsd]

I'll have to check next time I'm at the dealership. Called GM Roadside assistance and they towed it to the Chevy dealer here in Taos. They originally wanted to tow it to a GMC dealer in Santa Fe because the Chevy shop wasn't pulling up on their end. After providing the address they were able to confirm they were certified. I'll check back when it I get a chance.

Is the motor code also on the door or does the dealer need to look it up?

The motor code is in a tough spot but maybe the dealer can tell you. The dealer can look up your VIN to find the exact build date too.

The engine build date is in Julian date format but it’s tough to get too. It’s hard to describe where it is but it’s on the left side of the engine and to view it I had to crawl under the vehicle. If I remember it’s barely visible and I had to look in between the axel connecting the left front wheel and the frame. But I’m the dealer would know and look that up to confirm it falls within the bad lifter dates (thought that was Sept 2020 to Mar 5, 2021).

 

[wsteele]

Thanks for the advice. The Chevy dealer here in Taos is pretty small, so I thought the lead time was reasonable. Initially after hearing that lead time my plan was to drive the 60 miles to Santa Fe, but after reading about the issues, I decided I would have it towed to the dealership here in Taos. After calling them to schedule it she called me back to say her tech could look at it today if we can get it there in the next couple of hours. I mentioned the issues, warnings, and what I thought the issue was. When she called me back the tech thought it sounded "Electrical"..... So maybe I do want it towed to the GMC Dealership in Santa Fe...... On the line with Roadside Assistance to get it towed there now. We'll see what they say.

Good luck. Whatever the issue, it shouldn't take long for a tech to determine what the problem is, hopefully it won't be anything that entails backordered parts.