Originally Posted by zimaad
OK, here'* a better description of the noise. When the car starts up the */C makes a noise that almost sounds like something is jumping a gear inside. When the car is in park and the gas is applied the noise is not noticeable. When the gas is let off and the car goes back to idle the */C seems to jerk and make a clunk noise as it comes down near idle. I'll try the tubing trick and see if I can hear a bad bearing.
It is very likely the coupler. Follow Pdad'* suggestion, and get back to us. If it were a bearing, you'd hear it all the time. The coupler will typically only make noise at idle.