I have 1997 jeep wrangler 2.5l. Every time I go past 3500 rpm the belt moves towards the waterpump and the belt squeals because it grinds against the waterpump housing. I checked the belt tension (tried it tight as a guitar string and up to 4 inches of slack with no results), I have new idle pulleys, idle pulley bolts, a new water pump pulley and have tried a new belt. I cannot figure why I it does this, I'm scared ill chew threw a belt if I go around 4000 rpm. Also my idle pulley won't stop squealing. It spins on the bolt instead of the bearing I'm debating using some locktight to get the shim to stop spinning on the bolt.