Hi all, hope you're all well. Over the past 3 or so weeks my 2001 C5 has been making belt noises on start up (it went away after like 5 minutes or so). I went and got the fan belt changed 4 days ago, however the noise is still there. This morning I discovered the noise starts when I turn on the AC or when I rev the engine. Has anyone had a similar problem? From the research I've done so far I've found that it might be the idling pulley or the belt tensioner that may need replacing...other people have said that changing the belt for a Gatorback will help (but they also said this is just masking the noise and not solving the problem). Someone also mentioned that there's a second belt in there that may need changing...I'm confused as to what to do. Any thoughts or experiences? Thanks in advance.

 

There are two belts one is the main drive belt the other is the AC belt. It is not unusual for either the idler pulley or the tensioner pulley to go bad.

 

May well be the crank pulley - very common problem - take a look at it when the engine is running to see if it wobbles at all, the elastomer between the steel parts deteriorates and starts to separate....I chased mine around for a bit with a similar problem, new belts etc.....then just changed the pulley and all was good again....

 

Probably one of the pulleys,,,,I changed both,,,no more birds!

 

Had that problem, was worse when ac was turned on. Turnrd out to be ac tenioner and ac pulley. Good to go now.

 

Another thing that causes a "chirping like" sound in the T-body---especially on with an engine using an older FAST intake
The FAST noise is more of a whistle than a chirp--
The chirp in the TB occurs when the fuel trims are re-set--either by a battery dis connect or re-setting with a tuner--or adding some mods--( with new mods trims will eventually learn out) When the trims are way off for any of these reasons a chirping sound can be heard til the learning is close to being done--You can spray some Armoral on the suspected drive belts when you hear the noise--be careful with your fingers !! just a little on th pulleys---If it is indeed belt related--it will go away instantly( but will come back)
If it doesn't go away at all---then it's in the T-body and trim learning AND normal--IMHO

 

I change both pulleys and belt still makes sounds when cold turn up sound system

 

I think I'm having the same issue. Where did you get the new pulley and how much was it to replace? Thanks Bob

 

At autozone

 

I am having the same issue, which pulley was replaced? it cant be my belt because i just changed it. Thanks

 

I changed both the AC tensioner and AC idler pulley, problem fixed. Bought the parts from the Eckler's Corvette website (I can find them locally because I'm in New Zealand!).

 

First of all, do the water test on your belt to see if the chirping goes away. The water test: Get a spray bottle of water and with the engine running, spray a little bit on the belt and see if the chirping goes away. If it does, then the problem is probably with your belts. Be sure to check both belts. If the chirp goes away then you have a contaminated belt. You need to remove the belt, and clean all of the pulleys using a wire brush and brake clean. After you finish with the brake clean you'll need to clean that off and then install a new belt. Once a belt comes off the car, do not re-install it. It will undo all the work you just did. Always use a new belt.

If the chirp did not go away, then you have a problem with one of your pulleys. They may be mis-aligned, wobbly, or something else. The idler pulleys are usually the first to go bad. The pulley itself only cost about $15 bucks at O'Reillys. If you need the tensioner too then the whole unit cost about $70 at the same place. With the old belt still on the car, look at your pulleys to see if one of them is wobbly. Stop the engine and see if any of them are loose or something simple like that. If you find something wrong, just replace the pulley.

Do not use a belt dressing. It will not work.

Good luck with it. LS1 engines are touchy with their belts.

 

thanks for the response! I agree with you about the belt conditioners. I bought some spray on belt conditioner from autozone and it didn't seem to do anything. Interestingly the chirpy noise went away on its own. I did change the main belt and put the old one back on to see if it made a difference (Did this before I read your post) but the noise was still there. After a while it just went away on its own. I drove from socal to vegas and back no noise at all. weird. the harmonic balancer does seem to have a slight slight slight wobble but i noticed it since I bought the car and never seemed to make noises before...

 

update

the noise did eventually return. I replaced the AC belt and the main belt and that solved the issue immediately. Seems the whole time it was the AC belt that needed to be replaced. It had signs of extreme wear! this was months ago. Noise seems to be gone for good. thanks again for the help and support.

 

Did you replace with Gatorback brand belts? OEM belts are notorious for chirping. Keep that in mind if the chirping comes back - mine did.