Everytime I start my car when the engine is cold, I hear a very loud squealing noise coming from the accessory belt / pulley area. The sound usually lasts only a couple seconds or less, but sometimes it'll go for ~10 seconds, making it extremely difficult to diagnose. It stops just as abruptly as it starts, and I do not hear the sound again unless I let my car sit for a few hours or overnight.

I have ruled out the timing chain tensioner, because I know what that sounds like after hearing it in person. I have also ruled out the serpentine belt, since there is plenty of tension on it and the belt is not glazed or damaged in any way. The auto-tensioner is also working fine. My car has 35k miles on it.

I had the car looked at by a local mechanic over the weekend, and he was thinking that it could be a bad bearing on any one of the accessory pulleys. However, because the sound is hard to duplicate and lasts for such a short amount of time, it's extremely difficult to pinpoint exactly which pulley is making the noise.

Has anyone else had a similar problem? If so, what turned out to be the cause of the noise?

Here's a video of what I'm talking about... it sounds different on the video than it does it person--I think that may be because the sound is so loud that it drowns out everything else in the video:

http://www.youtube.com/watch?v=fanrxoSfyog

 

I think it's a belt

I would spray each belt, one by one to try to eliminate the possible culprit

I heard of people using soap, wd-40, silicon spray etc. I'm not sure what to recommend but perhaps someone can chime in.

 

That was my initial thought too, but I've tried WD-40, silicone spray, etc. and none have helped. I've also had a mechanic inspect my belt and tensioner, and he says that there's no way the belt could be slipping and causing that noise. The belt is perfectly fine

 

bump

 

temporarily run it without the belt.

that will rule out the pulleys and the belt.

 

Billman, what do you think about WD-40 and belts?

I would think it would add to belt slippage and be a no-no.

 

I thought that at least one of the pulleys would spin even without the belt on... is there any way to rule out the belt entirely without installing a new one?

 

That was my thinking too, but I have tried it on my belt and it caused no ill effects

 

WD40=bad idea.

Before you start the car in the morning, take the belt off.

If the noise persists, we can lean towards the starter.

If it goes away, shut it off and check the 5 pulleys by hand, make sure they all spin quiet and smoothly.

 

my bet is on the belt just the belt. not the pully. a belt doesnt need to be cracked or anything to make noise.

how many miles are on the car?