Str8ballin

What's up guys? Got a question. I have a 96 gle, and there seems to be a strange grinding noise coming from the belt side of my engine. I think it is the tensioner pulley. I've replaced the belts but the noise was there before. It has steady got worse over the last month. Only does it when the rpm s are low or at idle when I first start it up. I've loosend the belt and the nut on the pulley and the pulley spins freely itself. I backed off the tension on the belt but still the noise??? Anybody ever had this problem? Or does anybody know where I can get a replacement tensioner. No body seems to have one?