I started my car up for the first time in 2 weeks this past weekend. I heard the exact same thing. sounded like a rotating pulley squeal or a belt slip. It would come and go though. I don't think it's the belt. I am leaning towards the idler pulley. The sound was right there. Check yours out. Mine was fairly rusted. I wont drive it till we decide on a new bearing system. It's just not worth the risk......