Stange knocking sound

[tom q]

I hear a knocking sound behind the center subwoofer. I pulled out the cup holders and the sound is coming from that area.

Anybody had this problem? Is it an AC problem? Turned my AC on/off but sound is still there. Sound appears right out of a cold start and disapears when engine heats up.

 

[WHITEOUT]

does it sound like a knocking or air pinging? I had an exhaust leak, and at startup it would kinda tick, almost like a knock, but could tell it wasn't metal on metal. Does it sound like metal on metal? Turn on the car, get under it, and listen for the noise. You should be able to pin point it from under the car when it's making the noise. Hope that helps.

 

[tom q]

It literally sounds like knocking on plastic. I'll go under to check