Ok....Maybe I'm a little anal, but I have a squeak in the upper dash/cowl area of my 2004 GMC CC/SB gasser that drives me nuts. It seems to happen when the front end becomes unloaded. It will do it on bumpy roads as well as upon take off. Goose the pedal and it does it. Both brake and gas and it does it. With the plow on and in the up position it increases.
Noise is located in the front end of the truck. It is clearly heard from the inside of the truck. When the window it is open, it cannot be heard.
So far, I have:
1. lubed all 11 zerks
2. lubed all door weatherstrips
3. lubed front hood rubber stops
4. lubed underhood weatherstrip at the cowl
5.drove around with front shocks disconnected.
6.tore apart dash to no avail
7.moved some brakeline piping that was touching the master cylinder mount
8. took it to the dealer twice..

I'm pretty much at the end of my rope on this one....Driveshaft splines?...Upper A arm bushings?....Loose crossmember(s)?...Any help would be appreciated..Thanks...

Forget it...I figured it out.

JRKRACE -

Well...let's have it! What was the answer? I have an upper dash squeak myself...:help2:

OK..here goes...I don't know if this applies to diesels but this noise was sounding if it came from the dash area. I pinned it down to the area of the radio. As I began trying to make it happen, I noticed that if the truck is in park, the truck rocking back and forth would make the noise. I got underneath and tried to rock it back and forth and the noise came from the transmission area. Upon looking further, I found the son of a *****. It was a plastic clip that holds the tranny cooler lines together that was contacting the tranny tunnel of the floor.As the truck flexed the tranny, the clip would scrape the tunnel.