Squealing
Thread Starter
7th Gear
Joined: Mar 2012
Posts: 7
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From: Maryland
Squealing
So my C6 has a squeal that I am trying to figure out. I have searched through multiple threads here with similar issues but I don't see the same type issue so figured I would post a new thread. The squeal sounds like it's coming from the alternator. We replaced the belt (only the belt, no pulleys) just to see if that would help but it didn't. What I am finding that is different on mine from the other threads is that it squeals only when idling (so embarrassing to come to a red light or stop in traffic and the car starts making the dreaded loud squealing noise!). Once I hit the gas and start driving it goes away. Others have said the squeal appears while driving, but I am having the opposite issue. On my last oil change I asked them to tell me what the noise was and they said I need a new belt and tensioner (I am not sure how much I trust their assessment). We also pulled the tensioner back a bit to see if it would stop the noise and it didn't. So I am not sure if I should just switch out the alternator in hopes that's what it is...or try other things first. I am trying to avoid changing out too many things unnecessarily. Thanks!! 
Le Mans Master
Joined: Mar 2002
Posts: 8,466
Likes: 51
St. Jude Donor '17
So my C6 has a squeal that I am trying to figure out. I have searched through multiple threads here with similar issues but I don't see the same type issue so figured I would post a new thread. The squeal sounds like it's coming from the alternator. We replaced the belt (only the belt, no pulleys) just to see if that would help but it didn't. What I am finding that is different on mine from the other threads is that it squeals only when idling (so embarrassing to come to a red light or stop in traffic and the car starts making the dreaded loud squealing noise!). Once I hit the gas and start driving it goes away. Others have said the squeal appears while driving, but I am having the opposite issue. On my last oil change I asked them to tell me what the noise was and they said I need a new belt and tensioner (I am not sure how much I trust their assessment). We also pulled the tensioner back a bit to see if it would stop the noise and it didn't. So I am not sure if I should just switch out the alternator in hopes that's what it is...or try other things first. I am trying to avoid changing out too many things unnecessarily. Thanks!!
To test remove the belt so you identify if the sound is on the ac or main .
This will help you start looking at pulleys. The bearings dry out so you can start guessing and replacing parts if you want.
Just make sure the harmonic balancer is not wobbly. You might get lucky and just replace the tensioner or it may be one of the idler pulleys.
