Dash buzzing at idle after cold start

Njmurvin · December 2, 2020

It only does this when I first start the truck and the engine is cold. When I first start the truck, the dash buzzes pretty noticeably. It sounds like it's coming out of the center of the dash. At first I thought it might have something to do with the fan. But, even with the fan off, I get the buzz on a cold startup. When I put the truck in gear but still idling, the buzz gets slightly louder. When I accelerate, it stops. By the time I get to the end of my street to the first stop sign (a couple hundred yards), the buzz stops. Restarting with the engine warm, it doesn't buzz.

Anyone else experiencing this? I hesitate to have the dealer mess with the dash out of fear they'll create new rattles.

Mike Borowski · December 7, 2020

On 12/2/2020 at 2:20 PM, Njmurvin said:

It only does this when I first start the truck and the engine is cold. When I first start the truck, the dash buzzes pretty noticeably. It sounds like it's coming out of the center of the dash. At first I thought it might have something to do with the fan. But, even with the fan off, I get the buzz on a cold startup. When I put the truck in gear but still idling, the buzz gets slightly louder. When I accelerate, it stops. By the time I get to the end of my street to the first stop sign (a couple hundred yards), the buzz stops. Restarting with the engine warm, it doesn't buzz.

Anyone else experiencing this? I hesitate to have the dealer mess with the dash out of fear they'll create new rattles.

I have this EXACT same issue but I have the 2.7L. It's so annoying, makes the truck sound like a 30 year old pickup. I'm hesitant to take it in too, I'm sure they will say "that's normal".

Metalmainiac1158 · December 7, 2020

Yes sir, same problem on my 2020 2500hd duramax

Njmurvin · December 9, 2020

On 12/7/2020 at 11:20 AM, Metalmainiac1158 said:

Yes sir, same problem on my 2020 2500hd duramax

Have you had the dealer look at it? I don't drive it enough to be bothered that much by it since the truck is mostly used for towing my 5th wheel. I haven't taken it in yet for its first oil change because I only have 1400 miles on it. If it doesn't get any worse, I'll probably ask them to deal with it when I get my complimentary oil change (which could be late in 2021 if I don't start driving it more :).

Metalmainiac1158 · December 9, 2020

Have not taken to dealership as of yet. I tried clearing the code with a friend's reader, but it comes back immediately. It may be a cheaper code reader that can't perform the function properly. My back up camera stays on periodically with no trailer connected when I am backing out of a space as well. Current mileage is 1825.

1Joshman · April 17, 2021

I have had the same issue. Dash rattle. I have had the dealer look at and try a fix twice now and am talking it to another scheduled in two weeks.

Njmurvin · April 19, 2021

On 4/16/2021 at 8:39 PM, 1Joshman said:

I have had the same issue. Dash rattle. I have had the dealer look at and try a fix twice now and am talking it to another scheduled in two weeks.

There's a post regarding this problem on another forum. I don't know if it's OK to put a link to another forum.

In short, there are aluminum heater hoses behind the lower glovebox. They need to be tied with a wire-tie. Several people on that forum with this exact problem fixed it this way. I haven't done it. I plan to point this out to the dealer when I take it in for my free oil change service.

1Joshman · April 20, 2021

6 hours ago, Njmurvin said:

There's a post regarding this problem on another forum. I don't know if it's OK to put a link to another forum.

In short, there are aluminum heater hoses behind the lower glovebox. They need to be tied with a wire-tie. Several people on that forum with this exact problem fixed it this way. I haven't done it. I plan to point this out to the dealer when I take it in for my free oil change service.

I will absolutely mention this to them! Hoping for the best and will provide an update. Thank you

mkirkland · November 29, 2022

Not sure if its the same but on my 2022 3500HD, on cold start and initial drive i hear a faint buzzing, but to me it sounds like its coming from the drivers side upper dash area. As you said, once im a few hundred yards down the road, the sound goes away an i never hear it again until the next cold start

EzPz · February 12

Did you ever get an answer to this issue or figure out what it was? I am experiencing the same thing in a brand new 2026 Chevy Tahoe.

AndrewF · February 12

7 hours ago, EzPz said:

Did you ever get an answer to this issue or figure out what it was? I am experiencing the same thing in a brand new 2026 Chevy Tahoe.

Check the coolant overflow bottle bolts. They’re loose a lot of the time and cause a vibration. Once I tightened mine everything is quiet again.