Weid compresser noise
A/C makes a hollow and sometimes metalic sounding noise that goes up and down w/rpm's. This was only happening when the a/c was off. Once turned on, the noise went away. Removed the front clutch plate (not an electric clutch) and the noise went away. Put the clutch back on and noise returned. The clutch and pulley still look new as new can be. Took the inner serpentine belt off for the other accessories and the noise remained. Then took the belt off from the crankshaft briefly and the noise disappeared. I had the freon removed and the noise went away. Any ideas on the cause. This one even threw a curveball for the VW rep.