Squeaking Sound at Startup

[MercenaryZX]

Hi everyone, I have a recently purchased 2005 Grand Prix Base Model 3.8 Naturally Aspirated. There is a slight squeaking sound when I startup up the engine. Once it warms up after a couple of minutes it pretty much goes away entirely. Sounds like it's coming right around the fan belt area. The fan belt itself looks in great condition with no cracks or anything on it, so not sure if it's the fan belt itself or maybe something like the tensioner pulley or a bad bearing from one of the accessories like the alternator/water pump/power steering pump etc. Anyone had this issue in the past? I'm leaning towards the tensioner but can't say for sure.

[mguzzo]

well first off it's not a fan belt its an accessory belt but we know what you mean.

you can take the belt off and spin all the pulleys by hand and check for binding. spin the water pump too.
inspect and replace any plastic pulleys with metal ones. those bastards will melt and leave you stranded.

[MercenaryZX]

Sorry, yeah I meant Serpentine/Accessory belt. I found a quality aftermarket Continental belt for $40 that I'm gonna put on as it's pretty cheap so I'll do as you say and check the pulleys by hand while I do it. But the plastic pulleys really will melt? Gets that hot there?

[mguzzo]

when the bearing fails the plastic strips right off

[bandook]

Likely the tensioner. I've had two tensioners do same thing. You can test by CAREFULLY applying a little tension to the tensioner while it's running, noise will go away. Or spray it with a little wd40 or fluid film. It will get quiet for a bit but noise will eventually come back. I just live with it because it's only squeaky for a couple minutes and tensioners aren't cheap.

[MercenaryZX]

Likely the tensioner. I've had two tensioners do same thing. You can test by CAREFULLY applying a little tension to the tensioner while it's running, noise will go away. Or spray it with a little wd40 or fluid film. It will get quiet for a bit but noise will eventually come back. I just live with it because it's only squeaky for a couple minutes and tensioners aren't cheap.

I did the water spray trick, noise went away briefly then came back for a bit. But after a minute or two the noise goes away on its own away. The tensioner costs $160 Cdn in my area, bought a Continental Serpentine belt for $40 and will install it once I get it in the mail and see if the noise maybe goes away without having to replace the tensioner or any other accessory.

[MercenaryZX]

Likely the tensioner. I've had two tensioners do same thing. You can test by CAREFULLY applying a little tension to the tensioner while it's running, noise will go away. Or spray it with a little wd40 or fluid film. It will get quiet for a bit but noise will eventually come back. I just live with it because it's only squeaky for a couple minutes and tensioners aren't cheap.

Bought a spare Serpentine belt, haven't installed it because the noise has seemed to either greatly diminish or gone away lol. But I'll keep it just in case and one of these days I'll replace it and check the tensioner and other accessories when I'm not feeling so lazy

[BillBoost37]

Looks like you are pretty well set. I noticed you mentioned the plastic pullies melting. A lot of folks change out to metal to keep that from happening, except the actual point of failure is the bearing. If you change to metal the bearing has an issue, likely you are replacing both belt and pulley just like the plastic pulley. Instead, pay attention to sounds your car makes and you'll hear the bearing most of the time and be able to change out one pulley and not the belt.