HI all, I recently installed a new alternator and fan belt. A few days after there was a very noticeable squeaky noise coming from the alternator I had no choise but to continue driving it and the noise pretty much went away on its own. I still went and bought belt conditioner and sprayed some on. The noise never came back for about a week. Yesterday all was well no issues what so ever, drove to my gfs place then to work. After work there was still no issues, the car was silent as night. But when I pulled up to the drive way and put the ebrake on to get off and open the gate I hear a slight chirpy / squeaky noise coming fom under the hood. It's late as heck so I just go to sleep but the problem is still there. I drove it to work with the noise. Any ideas? at idle the noise is quiet but noticable but if you rev the engine it becomes louder. I have no clue where exactley it's coming from, except that its towards the middle. doesn't appear to be the tensioner or alternator.

I live in so cal not sure if the heat and random rain yesterday could be a part of this problem. that wouldn't explain how the car was fine then a second later the chirp appeared.

 

You can use a candle or bar of soap rubbed onto the contact side of the belts while the car is running. If it is just the belt it will stop. Do one belt and if it doesn't stop do the other. I'm guessing it would be your alternator belt since thats what you just changed. Be careful not to get your fingers or any loose clothing pulled in while the car is running. Lots of people say Gatorback belts work the best, you may want to try one of those if it keeps coming back. I've never had good luck with the belt conditioners on my vehicles it always seemed to come back worse when I used that stuff.

Also while your in there with the car running and a strong light watch the Harmonic balancer and see if it's running true or if there is a wobble to it. Some of the OEM balancers have had problems seperating from the bonded rubber and causing belt noise. If it is the balancer get it changed, can be expensive and difficult as the steering rack needs to be moved to access it. But if it fails completly it would be much worse on your wallet.

 

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 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. To address the harmonic balancer, it 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...

 

My chirp was the belt. Put a new Gates belt on the chirp went away for a couple months, then came back. I was on the Hot Rod Power Tour so I found a place that sold Gatorbacks and put it on. That was over a year ago and I haven't had a chirp since.

You can also use water in a spray bottle. Spray that on the belt and see if it goes away.

I actually used superior tire and interior dressing to diagnose mine. The soap probably works the best.

 

Check your harmonic balancer for wobble. It's a relatively common problem. Here is another thread with a similar condition;

http://forums.corvetteforum.com/c6-t...-chirping.html

 

Thanks for the reply guys I appreciate it, its good to know there is support here. The noise went away on its own and hasnt returned!

 

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! thanks again for the help and support.

 

This whole belt/chirp thing can get a little tricky.

First....could be one of two worn belts. Replace them rather than "treat" them.

Upper=accessory
Lower=AC

both upper and lower have idler/tension pulleys that can be going bad. Look for shaking or wobble or hold a listening device (garden hose?) up to them to see if they chirp.

If neither is the problem, watch your harmonic balancer and see if it holds steady and true or you see a slight wobble.

It can be any of the above but bottom line is to look and listen while it's idling in the driveway.

oh....and.....Good Luck

EDIT!!....I just went back and read that you found it...........NEVERMIND

 

most likely due to your coolant leak getting on your belt.

Be sure to keep an eye on your issue as you may have a failing waterpump seal.

 

I had to change out both a/c pulleys and went with Gatorback belts from my local pepboys.
3 months with no squeaks!

 

I just started having the crickets under the hood about a month ago. I went and bought belt dressing and sprayed it on. At first it stopped and then made the chirping actually worse. I read everything on here and since I have quite few miles on the car, I decided to change a bunch of things. At this point , before the work was actually done, on my way to the service I decided to experiment, just to make sure I have a better idea if it really IS the belts or something internal. So I sprayed some silicone lube on the belt, just to see if it will change the noise. It did immediately. So I was thinking "great, we change the belts and we are good". Well, not exactly. Put in brand new harmonic balancer, brand new upper belt tensioner and two brand new belts. Picked the car up and it was great....for about a day. Then the chirp came back. Right now I am waiting to put it back in. Any ideas are welcome.

 

Did you remove one belt at a time to diagnoise where the noise is originating before replacing your harmonic balancer?

I had chirping from my harmonic balancer once then on the tensioner pulley and then on the air conditioning tensioner pulley bracket.

 

LOL, in reading this thread had the same issues...but with my C3 exactly. Had no idea what was the cause. Kept driving it until the waterpump pully fell off. So check your water pump. It doesn't have to leak necessary when the bearings fail. Good luck.

 

Id suggest you check all the idler pulleys. If the pulley bearing spins freely, it is bad.