Vibration when accelerating only...

[powayvic65]

Hello all,
I have a 2021 GMC AT4 3.0 Duramax Diesel with 114K miles. Having vibration (never towed anything) when accelerating only on the highway at any speed...Runs great otherwise, getting 26MPH on the highway, 23MPH overall. What could be causing this?

 

AT4 Forum Fav 👍

PEDAL COMMANDER for GMC Sierra 1500/2500/3500 - Grab one through Amazon!

[Akcajunz]

did it just start vibrating all of a sudden? if so, Look at your wheels and see if you see any sign of a missing balance weight. Tire places like to use the stick on weights in the barrel of the wheel and sometime they will just come unstuck. Anyway, thats a quick look.

 

[powayvic65]

It runs fine, except when I accelerate. I can feel vibration from the engine.

 

[gemarsh]

Welcome.

If you have a bidirectional scanner, I'd look at injector pulses while driving under acceleration.

Sounds like a injector is failing.

 

[powayvic65]

My mechanic thinks it’s a torque converter issue

Welcome.

If you have a bidirectional scanner, I'd look at injector pulses while driving under acceleration.

Sounds like an injector is failing.

Thank you!

 

[R467X]

Have you done your timing belt service yet? That could be another cause and I'd bet that's what it js. Very expensive service.