98 C230 2.3 AC Problem? Belt Tensioner?
 

Another problem needs diognosis. :) I hear a knocking metal like clunking noise from the AC area. I think that my Clutch/Pulley on the AC Compressor is making the noise but not 100% certain. If I take it the the stealership they will charge me $200 just to diagnose it or just buy an ac Compressor with a clutch for 289 and install it myself. BUT... I read many forums that it could be the Belt Tensioner? How can I be certain? The AC pulley has a very minimal play when I move it back and forth, could this be the problem? ITs blowing super cold air. When I turn on heat everything is fine. As soon as I turn the AC on, clutch starts spinning and then I hear the clunking/metallic sounds. It happens even more when I turn the wheel all the way to the left or right. Help Please! Thank you. Just bough car 5 days ago.

The belt and tensioner spins all the time. The compressor only spins when the AC is on. If you only hear the noise with the AC on then that is a clue. Otherwise you can use a sounding stick, long screwdriver or mechanic's stethoscope to try to find the source.

It appears to be the AC going bad. Had 2 garages tell me its on its way. Thanks for the help!