Replace it..but first make sure that it is not an idler or tensioner pulley whinning.
__________________ 89 GT-gt40 ported heads with manley valves,cobra upr and lwr,E303 cam,1.7 Rollers ,pulleys,80mm Mass Air,190lph pump, MSD Ignition, 3.73's,Frp Axle Guirdle, tremec 5 speed,billet flywheel, Ford Racing Headers (Jet-Hot coated),Off Road X pipe, 24lb injectors, 70mm tbody,subframe connectors, aluminum driveshaft,HPM Megabite Jr. Lowers , 1" intake spacer,lakewood 50/50 shocks and 70/30 struts,Wild Rides Battle Boxes,2 stage dyno tuned chip,vortech S trim blwr @ 6psi | 
Noisy PS pump 99 3.8 
