My a/c system is "loading up" and i'm getting belt whip. Would this be the compressor,poa valve,or expansion valve. Any help from an a/c guy would be appreciated.

TRY TIGHTENING YOUR A/C BELT FIRST,THAN YOU WILL NEED TO HOOK UP A SET OF GUAGES TO THE LOW AND HIGH SIDE AND SEE WHAT THE PRESSURE IS ON BOTH SIDES.I THINK YOU WILL NEED TO TAKE IT TO SOMEBODY THAT SPECIALIZES IN A/C WORK TO GET IT PROPERLY DIAGNOSED.