I see you already have the PSK so it's definitely a bad bearing in your supercharger pulley. You can buy a new bearing from Needswings and then have your local NAPA (or wherever) press out the old bearing and press in the new bearing. I would suggest you do that while your deciding to upgrade to a 65mm pulley or not (don't run it with a failing bearing). Full repair on the OEM pulley should total under $75.00.