Squeaky sound from engine bay

[Traderjoe]

I have a 2005 Corolla with 47K miles on it.

When I'm parked at a red light (Transmission in Drive, brakes engaged, idling) I get this squeaky sound coming from the engine bay. If I'm in my driveway (transmission in park or neutral, doesn't matter if brakes are engaged or not), the squeaky sound is gone. I've replaced the belt on it already (it was cracking anyways), but the squeaky sound is still there. I've tried belt dressing to no avail.

What the heck is it?

[prophase]

I hate belt dressing and will never use it again, at one point it made the belt noise worse until it wore off.

Just an educated guess but maybe belt tensior.

Not sure if you used the Goodyear gatorback belt or not but if you did not, the new belt could start squealing pretty quickly again. This happens to my wifes 05 corolla. The goodyear belt has been on for quite some time and is only now starting to make some noise, or her tensioner is on the fritz.

[Traderjoe]

Originally Posted by prophase

I hate belt dressing and will never use it again, at one point it made the belt noise worse until it wore off.

Just an educated guess but maybe belt tensior.

Not sure if you used the Goodyear gatorback belt or not but if you did not, the new belt could start squealing pretty quickly again. This happens to my wifes 05 corolla. The goodyear belt has been on for quite some time and is only now starting to make some noise, or her tensioner is on the fritz.

I don't think I got the Goodyear belt. It was the more expensive brand from O' Rilley's though. It was squealing before the belt change, and it's squealing after.

Belt tensioner? The belt is always in contact with the belt regardless of gear (it squeals only in Drive. Not in Neutral or Park). Is there something I'm missing?

[prophase]

You do understand that a when the car is in drive or (D) if you have an auto (which I assume you do), the engine is under load, whether at a light idling or while driving. This load could be stressing the tensioner possibly or another pully on your engine.

When in nuetral or park and car is running, the engine idles freely with almost no load or stress on any of the engine components.

If your belt is really new and you're sure it's not the belt, could be belt tensioner or pully on one of the accessories possibly.

[silver04rollas]

Looks like a serpentine belt needs to be replaced.

[invader]

Load on accessory belt and tensioner isn't higher in drive compared to neutral... It was squealing before, and still does with the new Gates belt from Oreilly's.

Could you get a sound clip of the said squeek from under the hood?

[Amber]

What happens if you rev the engine a bit while in 'D' and holding the brakes? Does the frequency of the squeal stay the same, increase with engine speed, or go away?

[Josh.Chaos]

Check the tensioner, like they said... I had the same problem. I got a brand new tensioner from a friend who used to work the toyota parts dept, and I have been squeek free (with my gatorback), for about 25k miles...

[Traderjoe]

Okee Doke! I'll try replacing the tensioner and alternator pulley. Thanks!

One last thing. Is the engine under more load when in D (drive) than in Park? It's weird because in both Drive and Park, I rev to about 2000RPM and I only get squealing when in Drive. But the belt goes around the same components. What's the difference?

[invader]

Originally Posted by Traderjoe

Okee Doke! I'll try replacing the tensioner and alternator pulley. Thanks!

One last thing. Is the engine under more load when in D (drive) than in Park? It's weird because in both Drive and Park, I rev to about 2000RPM and I only get squealing when in Drive. But the belt goes around the same components. What's the difference?

Engine is under load through transmission in Drive, but not in Park. Load on serpentine belt is the same at 2000 rpm, whether it's in Drive or Park... What exactly is squealing or squeaking? Try to isolate the noise source.