When I first start the car in the morning I hear a sound from engine compartment just after I get rolling that *sounds* like the A/C compressor clutch engaging. I don't think it is the A/C because I get the same sound whether the A/C is on or off. This occurs only after the car's been sitting a while (overnight, etc.)
I've got a '97 2.8 with automatic tranny. The sound doesn't seem to be synchronized with the transmission however...