starting noise

[ThE_BoMB]

Well I got a used 1991 240sx the other day and I noticed a noise now when I started it up after having a bit of fun in my new car, first it starts goes to 1500 ish rpm then goes way down round 150 then a screech and it back up to 900, I thought it might be a belt but does anyone have any suggestions?

[Apparition]

If its a high pitch squeal and eventually disappears its the pulleys. I had this replaced and it fixed that problem.

[thx247]

you can check the belt deflection by just pressing on the belts and seeing if any are lose. Also check bolts holding tensioners in place and see if any are lose, I had a bolt rubbing against the power steering pully once. Sucked.