Serpentine Belts
Saturn S-Series

What does the idler pulley in a Saturn SC series actually do for the car?



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Idler pulley takes up the extra slack from the serpentine belt.Serpentine belt, drives accesories from the crankshaft ie., usually,. water pump, power steering pump, alternator,air conditioner compressor. Older vehicles had separate belts for driving these componants and each had it's own adjustment location which was done manually,[which is why belts would schreech when loose] most of the newer stuff has idler pulleys which are self adjusting [spring loaded]the bad part is serpentine belts can be pricey and the bearing in the idler pulley can tend to wear out and the whole unit has to be replaced. L. Keedy

The belt tensioner actually loads the tension on the belt The idler pulley on a Saturn actually just maintains a balance of pressure on the pulleys. It runs between the P/S puimp and A/C compressor on vehicles that have p/s and a/c. The belt from the dealers is only $35 Canadian That's not expensive at all