Noise while driving

[sllewm]

New to the forum and noticed I asked this on a thread that was almost a year old so thought I would start a new.

I just bought a 2024 2500hd 6.6l gas Silverado Custom.  I hear a buzzing type of noise coming from behind the dash.  Sounds like a grounding type of static that fluctuates with the engine rpm.  Does not matter if engine is hot or cold.  Loud enough to drown out engine noise while driving.  Dealer has no idea.

Anyone have this issue with your custom and if so have you got a fix?

[sllewm]

Well, 77 views and no responses so I guess this shows that it is not  normal.  Now to figure out where it is coming from.  

[BuckWallace]

I'd have said it might be the power steering pump, but that's usually only noticeable at idle and goes away under throttle. Does it sound like a vibration? Maybe some loose trim rattling around?

[sllewm]

Thanks for the reply.  No it fluctuates with the rpms of the motor.  Can replicate it in park reving the engine.  Tried using a stethoscope on the steering pump and AC along with the altenator and all was good.  Sitting in truck I hear it best above cluster guages.  I do not have digital guages.  Dealer doesn't think it is the stepper motors behind dash.

Would a torque converter make this noise?

[Mike O.]

Hi just saw this. I have a 2025 2500 6.6 L8T custom also, my truck makes the same noise you describe. Almost like a bad ground on a stereo through the speakers. I’ve had passengers ask if I had a turbo or supercharger. I only have 1400 miles and haven’t taken it in yet. I also have a bad vibration at around 4k rpm. Pretty annoying ! Did you get it figured out? Thanks in advance, Mike

[M.Douglas]

2026 HD2500 ZRT Gasser with same noise. Have been loyal to GM but this will be the last if they can’t fix it. Sounds like a toy drill motor in the dash at lower RPMs (<40 mph) until other noise drowns it out. Cannot hear it outside. Taking mine to dealer next month with only 700 miles on it. Let me know if anyone else has found a corrective action. Thanks.

[AndrewF]

Check the tightness of the coolant overflow bottle bolts. For many people they loosen (me included) and cause noise in the cab.
 

Once I tightened them i haven’t heard anything since.