Engine noise, sounds like a pulley...

[Dennis C]

Hello all. I have a quick question regarding pulley noise in my 996. It has done this ever since I bought it, and I don't know if it is normal or not. It almost sounds like an air conditioner pulley noise. If I turn off the air conditioning, it still makes the noise. The noise increases with engine speed, to a point. If I let off the gas, it goes away, and returns when I step on the gas.

I only really notice it when driving on the highway, with the radio off and the windows closed.

Any thoughts?

[GranburyChuck]

I had a similar occurence on my 996. One was a whining sound "like a turbo rush". Didn't notice it so much at idle so I couldn't tell it when not driving. Took it to the dealer and they used a scope to determine it was the alternator bearing. I replaced the alternator myself. Second time it was the water pump. Had the dealer replace that one. Has your belt been replaced?

[Dennis C]

I had a similar occurence on my 996. One was a whining sound "like a turbo rush". Didn't notice it so much at idle so I couldn't tell it when not driving. Took it to the dealer and they used a scope to determine it was the alternator bearing. I replaced the alternator myself. Second time it was the water pump. Had the dealer replace that one. Has your belt been replaced?

My belt was replaced at the 60K service.

This does sound like it could be a bearing of some kind, and I had actually thought about the water pump...

[Loren]

I suggest you remove the belt and see if any pulleys wobble when spun. Even an idler pulley can do major damage if it breaks while running.

[Geldgrube]

I suggest you remove the belt and see if any pulleys wobble when spun. Even an idler pulley can do major damage if it breaks while running.

That's good advice from Loren. I recently had the same problem.....removed the belt and found one of the idler pulleys to be running rougher than the others (it's VERY easy to tell simply by spinning it by hand and listening). Cheap fix.

Good luck, Ron

[Dennis C]

Thanks for the advice Loren. I'll plan to do that.

I'll add it to my DIY list, along with the passenger's side window regulator that I'm planning to replace soon!

[judgejon]

Thanks for the advice Loren. I'll plan to do that.

I'll add it to my DIY list, along with the passenger's side window regulator that I'm planning to replace soon!

Yes, Loren's right. I had to replace the idler pulley near the alternator. Made a whistling-type sound similar to what you describe. good luck..

[bradmay]

Hello all. I have a quick question regarding pulley noise in my 996. It has done this ever since I bought it, and I don't know if it is normal or not. It almost sounds like an air conditioner pulley noise. If I turn off the air conditioning, it still makes the noise. The noise increases with engine speed, to a point. If I let off the gas, it goes away, and returns when I step on the gas.

I only really notice it when driving on the highway, with the radio off and the windows closed.

Any thoughts?

I experienced this last year with my '02 C2 Coupe. It turned out to be the alternator bearing. The noise was most noticeable at low RPMs sitting at stop lights. It wasn't a problem at speed during highway driving.