Bad Idler pulley?

Dr Fildo · Nov 12, 2010

I have a sound under the hood that rises and falls in pitch with the RPM's. Kinda sounds like a supercharger. I don't think it's the alternator b/c it was replaced not too many miles ago and when I put my ear close to it, I don't hear the sound. Could it be the idler pully? Not sure it it has ever been replaced. How often do these things go bad? I have about 161k on the clock, pretty much bone stock.

If it could be the idler pulley, what's the best kind of replacement?

modo · Nov 12, 2010

Dr Fildo said:
I have a sound under the hood that rises and falls in pitch with the RPM's. Kinda sounds like a supercharger. I don't think it's the alternator b/c it was replaced not too many miles ago and when I put my ear close to it, I don't hear the sound. Could it be the idler pully? Not sure it it has ever been replaced. How often do these things go bad? I have about 161k on the clock, pretty much bone stock.

If it could be the idler pulley, what's the best kind of replacement?

take the belt off and start the car for a second. if the noise is not there then you know the problem is one of the accessories. try to wobble the pulley, it shouldn't have any side to side plan, if it does then it should be replaced. if the sn setup id the same as the fox you can just get a new pulley for it vs the whole unit. stock or stock replacement is fine. 160k is a good life out of it

Cox98Gt · Nov 12, 2010

also check your tensioner those go bad also

OnyxCobra · Nov 12, 2010

I just replaced one on my dad's car, besides the sound it was making I took the belt off and there was one pulley I couldn't even spin by hand. If it's that loud it's probably grinding pretty bad.

Dr Fildo · Nov 16, 2010

Definitely going to try that. Great Idea. Thanks.

Dr Fildo · Dec 3, 2010

Well, I replaced the distributor and the sound seemed to disappear and the no start issue went away. Car ran great. Problem solved. Until this morning, when I was at a stop sign. I was making a left and when I started the turn...no power steering. I pulled to the side, turned her off, and opened the hood. The idler pulley seized. Serpentine belt shredded and the pulley actually melted off. I guess I had a dual problem. Funny thing - it made no sound whatsoever as it melted down & shredded.

Does anyone know the size torx bit I need to change the idler pulley?

Dr Fildo · Dec 4, 2010

The correct size Torx bit for the idler pulley is T-50; same as the belt tensioner pulley, for future reference, in case anyone is interested.

Can you say "Catastrophic Failure?"

I got a metal replacement from Advanced Auto Parts for $34.99.

CC'S95GT · Dec 4, 2010

you got quite a rats nest in there to clean up.
hopefully there is nothing else

Dr Fildo · Dec 4, 2010

Cleaned up ok. Not worried about the plastic shavings. I did find a few of the ball bearings on the manifold in some strage places. I hope I found them all.