Use a straight edge.
pulley puller
Begin by loosening the tensioner pulley on your 1999 Oldsmobile Cutlass. Put your serpentine belt around the pulleys. Tighten the serpentine belt with the tensioner pulley.
it is self adjusting .
On front cover of engine by crankshaft pulley.
bottom pulley. at end of crank.
The part number is 587260
Serpentine belt and pulley diagrams at www.alldatapro.com
When looking at the engine from the front, the tension pulley is the only wheel on the drive belt that has the belt on the inside of it. All of the other pulleys have the belt going around the top of the pulley. The tension pulley has a bolt that can be loosened and then tightened to remove the drive belt.
check main pulley area bottom by harmonic balance
The camshaft position sensor is located behind the water pump pulley. If looking directly at the pulley, it is at about the 10 O'clock position. TechJK ---------------------
air conditioner eliminator pulley from autozone.com
you must have a pulley that has a bad bearing i would take and spin each pulley with the belt off and see what one dose not spin freely and replace