Thread: 1998 Grand Prix noise under the hood

Okay, so I have always had a problem with a noise under my hood, I always figured it was my super charger coupler, so I order a ZZ coupler and replaced it, then half the noise went away, the super charger is quite now.. But there is still noise.. Now when I spin some of the pulleys with out the belts on there sounds like they have dirt or something in there, like a bad bearing in a skate board if you know what I mean.. Then If i spin my alternator pulley, the fan in side the alternator is very squeaky and loud.. So 'm not sure if i should replace both.. any ideas?


1998 Grand Prix belt noise - YouTube

Well if the pulleys are stock they could be going bad, same with the alternator. Run it without the supercharger belt and see what happens.

Already have ran it without the belt, makes the same noise

It doesn't sound like the idler pulley that makes a squeaky noise usually. I would guess one of the bearings in the alternator is bad.