Thumping under dash

pascopatio · 09-24-2008, 03:54 PM

Hello Newbie here. My wife has a 05 500, upon starting the car there is a thumping sound under the the dash on the passenger side, I figured airbag? but it also happens when the ac is turned on or off. Any ideas? veh. is out of warranty so any help will be appreciated.

pascopatio · 10-01-2008, 11:55 AM

No idea's??

phantom_smack · 10-01-2008, 11:59 AM

single thump or thumping ?

theoldwizard · 10-01-2008, 12:38 PM

Why would you think it was the air bag ? With the equivalent of a 0.1-0.25 stick of dynamite inside one, you had better hope it is bolted down well !

froggerxt · 10-01-2008, 06:57 PM

Don't you know it is "The Monkey in the Trunk"

I am sure you have seen the videos on You-Tube.

Really maybe something is loose.

Jerry

pascopatio · 10-03-2008, 03:06 PM

At first I thought air bag as it happened right after you started the car, you would hear 4 or 5 thumps ( like you were flicking your finger on the dash hard) best I can explain the sound, then it started happening when she turned the ac on. Guess I will have to take it to the stealorship.

theoldwizard · 10-03-2008, 06:09 PM

Wild guess. The heater fan spinning up and knocking against the housing ????

phantom_smack · 10-04-2008, 07:50 AM

Sounds like its the fresh air door it defaults to fresh air position according to the hotline and when the vehicle is started it will close the fresh air door and like the auxilary air on an Expedition when the motor gets out of whack it tries to reach a certain point but botoms out a pops several times .

pascopatio · 10-04-2008, 10:18 AM

I really appreciate the help. Now it has stopped making the sound for two days, i'll check thoses ideas and see if anything is up.