i have an 01 3.2 and the compressor, or something associated with it, makes this loud noise once the car has warmed up. the a/c clutch kicks on when the defrost is on and once it shuts down there is this loud sound. kinda like a muffled air horn. i switched the idler pulley hoping that was the problem, but no go. is there something else that engages/disengages that makes the clutch switch off? i know the system has never been purged or recharged yet at approx. 100k. any thoughts as to what the noise could be?? thanks for any input anyone can offer....