Seirra AT4 died on interstate

Andre F. · Mar 17, 2025

At4 w 13K simply quit on interstate while pulling my trailer. 2024, 6.2. Battery was down to 11.8...got a new battery. Installed it. Read 12.8. Truck wouldn't start. Did clickbeach time i tried to start her. No warning lights, engine lights, Battery lights at all. Remote diog from GM, nothing noted. Dash is up, nav screen up. Simply won't start. Also won't shift out of park to natural. Honestly really let down by gmc. Towed to dealer. Now sit and wait. Ruined a 40 day trip!

jakrbt · Mar 17, 2025

Any other signs when it quit? Noises? Loss of acceleration?

gemarsh · Mar 17, 2025

Does it crank over, or just click or not even click?

1. If'n it cranks over, look at the fuel pump module on drivers frame rail.

2. No click, look at the starter fuse on top of battery. Won't do any good to replace now, cause the engine is/will be toast.

3. Clicking, could be several things.

Good luck.

TJ.Turner · Mar 24, 2025

Andre F. said:
At4 w 13K simply quit on interstate while pulling my trailer. 2024, 6.2. Battery was down to 11.8...got a new battery. Installed it. Read 12.8. Truck wouldn't start. Did clickbeach time i tried to start her. No warning lights, engine lights, Battery lights at all. Remote diog from GM, nothing noted. Dash is up, nav screen up. Simply won't start. Also won't shift out of park to natural. Honestly really let down by gmc. Towed to dealer. Now sit and wait. Ruined a 40 day trip!

Andre - I have a 2023 AT4X AEV and experienced exactly the same issue, with the exception of purchasing a new battery. NHTSB is investigating our 6.2L engines as this is prevalent in the Sierra 1500, Yukon's and Escalades where Bearing Rods are failing at a very high degree.

gemarsh · Mar 24, 2025

TJ.Turner said:
Andre - I have a 2023 AT4X AEV and experienced exactly the same issue, with the exception of purchasing a new battery. NHTSB is investigating our 6.2L engines as this is prevalent in the Sierra 1500, Yukon's and Escalades where Bearing Rods are failing at a very high degree.

I'm not correcting, I'm teaching.

Coming from a gearhead, it's called a Rod Bearing. When I read bearing rod, it is like finger nails running down a chalkboard.

There are gobs of people that don't care/know the correct nomenclature of parts that make up vehicles. And that is fine, I made a living with that clientele. I don't do law or politics, but I would like to be taught correct terminology, if'n I miss spoke.

TJ.Turner · Mar 24, 2025

Fair....just remember I before E except after C....I get the Fingers on Chalk boards.....LOL I'm not a gear head, but love my truck and extremely aggravated with this situation.

GhostSage · Mar 24, 2025

I had my lifters on my ‘21 at4 go out at 800 miles. 5.3 L and I was pissed. Spent 2 weeks at the dealer and no car.

BlueBrute · Mar 25, 2025

gemarsh said:
I'm not correcting, I'm teaching.

Coming from a gearhead, it's called a Rod Bearing. When I read bearing rod, it is like finger nails running down a chalkboard.

There are gobs of people that don't care/know the correct nomenclature of parts that make up vehicles. And that is fine, I made a living with that clientele. I don't do law or politics, but I would like to be taught correct terminology, if'n I miss spoke.

There you go again debating the differences between dohickies and thingamajigs!

BlueBrute · Mar 25, 2025

I wonder if there will ever be a true discovery of what is really causing these engines to crater? Even worse, will there ever be a correction to the problem if found? It's so discouraging that we can't buy a vehicle anymore that you can even imagine going 100k miles. True craftsmanship seems to be a thing of the past, and never coming back.

GhostSage · Mar 25, 2025

BlueBrute said:
There you go again debating the differences between dohickies and thingamajigs!

Don’t forget about the thingamabobber

Wildcatfan · Mar 25, 2025

With all of this bad new swirling around the 6.2, yall have me worried. My 24 AT4 is sitting at just over 5200 miles. I am hearing on start up, what I would call valve chatter. Is that common with the 6.2 or is this a sign of things to come? TIA

GhostSage · Mar 25, 2025

Wildcatfan said:
With all of this bad new swirling around the 6.2, yall have me worried. My 24 AT4 is sitting at just over 5200 miles. I am hearing on start up, what I would call valve chatter. Is that common with the 6.2 or is this a sign of things to come? TIA

Lol for real. Mine has 300 miles and im already sweating bullets

jakrbt · Mar 25, 2025

Wildcatfan said:
With all of this bad new swirling around the 6.2, yall have me worried. My 24 AT4 is sitting at just over 5200 miles. I am hearing on start up, what I would call valve chatter. Is that common with the 6.2 or is this a sign of things to come? TIA

I know exactly what you're talking about and I would love to be able to tell you it's "normal"......but seeing as my truck is sitting at the dealership for the next 4-6 weeks waiting on a new engine.....

Wildcatfan · Mar 25, 2025

jakrbt said:
I know exactly what you're talking about and I would love to be able to tell you it's "normal"......but seeing as my truck is sitting at the dealership for the next 4-6 weeks waiting on a new engine.....

Just curious, did you notice or hear something like valve train chatter on start up?