Wife's 2008 3.2 AWD started making a slight knocking sound from the front a month or so ago that got worse with the AC on. It got really loud this weekend so I popped the hood and the AC compressor pulley has a noticeable wobble (AC is still ice cold) that seems to be creating the sound. Sound goes away when AC is turned off. I've read around and it seems a new compressor is on deck. My questions are: 1)any chance its not the compressor itself but the pulley? And 2) can it be driven with the AC off without risk of inflicting damage? I'd like to order the parts online rather than get fleeced at the stealership but she needs transportation in the meantime. Obviously would rather be inconvenienced than risk further damaged though. Any help would be appreciated!