Chirp / Squeal
Thread Starter
Instructor
Joined: Jul 2003
Posts: 131
Likes: 2
From: Fairfax, VA
Chirp / Squeal
I have a 2004 coupe with a stock LS1 engine and 123,000 miles. Lately I have been hearing a chirping sound. The sound is a series of 4 or 5 chirps a pause then a repetition. I don't think it is a belt, pulley, tensioner, or idler squealing because it occurs on a cold start and subsides after a few minutes to silence. Any thoughts?
Team Owner
Joined: Mar 2001
Posts: 21,325
Likes: 3,841
From: small town in S.E Pa. PA
St. Jude Donor '03-'04
yeah , I think it is a tensioner or idler pulley bearing... soon as the bearings warm up they redistribute the grease which after 120,000 + miles is about shot, dried up, ineffective. what little is left heats up and silences itself.. the problem is each time this happens you lose some more lubricity. you have 2 tensioners and two idlers, its best to replace them all since the grease that is used see the same rpm... the onlt difference is the amount that is still remaining..
you dont need new tensioners only the bearings the ac belt system bearings are different than the drive belt bearings.... the drive belt uses the same bearings for the tensioner and the idler. you can start with them... the bearings by themselves are around 20 dollars each..16 dollars if you get a discount..
you dont need new tensioners only the bearings the ac belt system bearings are different than the drive belt bearings.... the drive belt uses the same bearings for the tensioner and the idler. you can start with them... the bearings by themselves are around 20 dollars each..16 dollars if you get a discount..
Melting Slicks
Joined: Oct 1999
Posts: 2,581
Likes: 14
From: Tolar Texas
I like Evil-Twin's suggestion about replacing the just the bearings vs. the whole tensioner or idler pulleys. I'll go that route when my bearings begin to make noise.
My car had started to "chirp" in the same way that you are describing. My first guess was that one of the idler or tensioner bearings was failing.
Following a suggestion found here on the CorvetteForum, I was able to isolate the source of noise by using a squirt bottle filled with water. I squirted water on the A/C belt and the chirping sound would stop for a few seconds.
While the engine was running, I cleaned the belt using a small wire brush and soft scrub abrasive cleaner. (GOJO hand cleaner might work well too). This has stopped the noise for 3 or 4 weeks.
A new belt would probably be the sure cure but cleaning the belt might buy you a little time IF indeed your chirp is belt induced.
Please be very careful if you attempt to clean the belts using the method described. The possibility for disasterous injury or death is obvious.
Be sure to post a follow up letting us know what you find.
My car had started to "chirp" in the same way that you are describing. My first guess was that one of the idler or tensioner bearings was failing.
Following a suggestion found here on the CorvetteForum, I was able to isolate the source of noise by using a squirt bottle filled with water. I squirted water on the A/C belt and the chirping sound would stop for a few seconds.
While the engine was running, I cleaned the belt using a small wire brush and soft scrub abrasive cleaner. (GOJO hand cleaner might work well too). This has stopped the noise for 3 or 4 weeks.
A new belt would probably be the sure cure but cleaning the belt might buy you a little time IF indeed your chirp is belt induced.
Please be very careful if you attempt to clean the belts using the method described. The possibility for disasterous injury or death is obvious.
Be sure to post a follow up letting us know what you find.
Le Mans Master
Joined: Mar 2002
Posts: 8,466
Likes: 51
St. Jude Donor '17
yeah , I think it is a tensioner or idler pulley bearing... soon as the bearings warm up they redistribute the grease which after 120,000 + miles is about shot, dried up, ineffective. what little is left heats up and silences itself.. the problem is each time this happens you lose some more lubricity. you have 2 tensioners and two idlers, its best to replace them all since the grease that is used see the same rpm... the onlt difference is the amount that is still remaining..
you dont need new tensioners only the bearings the ac belt system bearings are different than the drive belt bearings.... the drive belt uses the same bearings for the tensioner and the idler. you can start with them... the bearings by themselves are around 20 dollars each..16 dollars if you get a discount..
you dont need new tensioners only the bearings the ac belt system bearings are different than the drive belt bearings.... the drive belt uses the same bearings for the tensioner and the idler. you can start with them... the bearings by themselves are around 20 dollars each..16 dollars if you get a discount..
Thread Starter
Instructor
Joined: Jul 2003
Posts: 131
Likes: 2
From: Fairfax, VA
I'm taking the Evil-Twin "belt and suspenders" approach and replacing all four bearings and both belts. Why? Because time is money and my time is not worth much money - probably about $5 per hour. I figure I can spend 8 hours replacing these parts and I am still ahead of the game. Thanks all!
Last edited by FussBudget; Aug 3, 2008 at 09:36 PM.
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Melting Slicks
Joined: Feb 2002
Posts: 2,956
Likes: 2
From: Indianapolis In
Lets hope it is not the alternator. I had the "chirp" that went away when the car warmed up. I changed the belt & tensioner and the noise went away. a couple of weeks later, the alternator locked up. It appears the rear bearing was bad & when I changed tensioner, there was new amount of tension on the system & the noise went away. I Only have 35K on the car. I hope you don't have the same problem.
