well it's still making boost, still runs fine, i sprayed some wd-40 on the idler tensioner pulley and blower pulley bearings and the sound seems to have gone away......
i have the 04 cobra hood w/ the hood vents opened and it rained yesterday, so im thinking the water got on the pulleys bearings...
I have a noise in my 99 P1SC as well. The Procharger smooth idler pulley (the one off the front of the alternator bolt) sounds fine and smooth, so I think it is one of the Ford idler pulleys. I pulled the alternator off and put it on my 01 just to make sure and it sounds fine, so I ordered a new smooth idler pulley and a tensioner arm (I cannot find just the tensioner pulley alone). Hopefully, I will get them on tomorrow and see if the noise dissapears.
From Ford, the idler pulley is $19 and the tensioner arm and pulley is $68 or so.
yeah i just checked again and it's the pulley right under the charger but above the idler tensioner pulley thats rubbing the metal arm... it's diagonal from the alt. pulley.