[Ash23k]

Recently purchased a 2011 cxl. Last night i noticed a thumping noise behind the glove box after starting the car. The noise only last a minute maybe then goes away, but it happens every time the car is started.

 

[rbarrios]

thumping/clicking/thumping is usually associated with broken teeth on the actuator that moves every time the vehicle is started.
the noise is the gears reaching the point where the teeth are missing- and it literally skips

does it sound similar to this?
this is the Impala.

 

[Adransoff4]

Replacing the air inlet actuator ( the one behind the glove box) is possible without removing the dash. Did it last night. You will need to remove the Aux actuator ( passenger side) to have enough room for hands and tools to remove T20 screws on the air inlet actuator. Top screw is a blind grab. If using a T20 bit in a socket, use tape to keep it from coming out or have a bunch of bits- lol I moved the passenger all the way back, lay on the floor and wearing a head lamp for lighting. If you have bear paws for hands, this may not be possible. Hope this helps someone from spending a boat load at the stealership to get this replace.