Ever since about a couple of months after I bought my new truck, I hear a rattling noise on top of the dash on the passenger side. It only does it when I start off from a stop. My brother in law just bought a GMC Acadia and he also has the same problem but his is on the left side of the dash in front of the driver. Does anybody know or have heard this sound? Does anybody know how to fix it?

 

I don't know if your sound is the same, but...
My truck started with a right side dash board rattle sound that I had only upon acceleration and I swore it was something loose behind the dashboard. It turned out to be sympathetic vibration from a front skid plate. Really!
I suspected it was something away from the dash because I saw someone look over from the sidewalk once when it happened. To test my SWAG (Scientific Wild A Guess) I loosened the plate and the noise was gone. To permanently (I hope) stop the noise, I slightly re-bent the plate along one (just one) of the two longitudinal creases in it, changing its radius. then the plate was reinstalled tightly and with anti-seize in case I ever have to take it off again. This broke up the complimentary harmonics, stopping the dash board symphony. I've got more noises, but at least this one's gone. I sure thought it was something in the dash, like the nut driver I haven't been able to find since installing my XM Radio.

 

A problem often found with gm trucks and what is at first noted as dash noise is acually a bad steering shaft. As the problem gets more intense you will begin to feel a vibration in the steering wheel mainly on turns and then you will notice it in the brake pedal as well, be sure to check out this issue. I have replaced the part on my 04 gmc sierra 2 times before finding that gm had released a new design and i have recently installed that part witch seemed to solve the problem.

 

No I know for sure its not the steering shaft, I used to have an 03 Z71 and it did it all the time so I'm familiar with that noise. I'll have to try and check out the skid plate (sounds like a good idea) and see if thats the cause. I just feel like its almost on top of the dash. I noticed the new body styles have two pieces on top of the dash which the rattle might be coming from a connection between the two pieces. Thanks for your ideas.

 

this is at low speeds?

 

Yes, the noise happens right as a start from stop. Goes away after 10-15 mph.

 

i'd just have to hear it..if its inside the dash for sure,its probavbly the onstar/xm box (if equipped)..has the dash been out before?..did it have an onstar upgrade?

other common rattles are a/c lines rubbing the firewall outside,and nerf bar steps rubbing the frame underneath

 

Dash has never been out before and the truck came with xm/onstar already installed. I think I'll just have to take it to the mechanics and the dealership and see what they think.

 

ok, now i have different noise, i have an 08 gmc sierra 1500 crew cab 4x4 Z71, with 50 000kms already, i have a vibration under my steering wheel, the lower dash when i press my knee against it it goes away, how do i pull off that panel, so i can stop vibration? only noise in my truck!!!

 

Likely a broken dash tab or something is loose. I used some thin foam for home window insullation and it worked for stopping the noise.