I took my 97 f150 in to the shop for this grinding noise. They said that the A/C compressor was bad. The compressor puts out cold air but the magnet on the front was bad. I put a new clutch magnet on the compressor. the noise is still there. Someone said their truck had that noise and it was the water pump. Any answers?

 

if you here grinding and some vibration it usually is your water pump dont wait to long . and you may hear some squeling as the bearing gets worse

 

Your best bet is to remove the serpentine belt and turn each pulley individually slowly to figure out which pulley has a bad bearing in it. I had to do this with my wife's 95 Firebird at least three times a year...first the car ate alternators like they were ribeyes, then the idler pulley went bad...you get the picture. It'll be easier to figure it out without the belt on, but you have to listen close...