Hi,
I have a 1997 Chevy Cav (4 cylinder, 5 speed, 133,000). It is a great little car that my dad gave me. He bought it new and it has had very little problems.

I recently had the serpentine belt changed (3 weeks ago). Right after the belt was changed I noticed this high pitch whining/humming sound when in neutral, 1st, 2nd, and 3rd gear. I brought it back to my mechanic and he said the noise was fine and not to worry about it. I don't necessarily disbelieve him as I have had great service from him in the past. However, this sound is really bothering me and I'm not sure if I should bring it back in again to have it looked at.

I'm not sure if it was simply a coincidence if this humming/whining sound started after the belt was changed or if it has something to do with it or not. All I know is that the car's engine was not making this noise prior to the new serpentine belt.

Anyone with sugggestions about what this noise could be attributed to or if this is normal after a new belt would be much appreciated! Should I take it in again? What are some things I should have my mechanic check? He checked the alternator and found nothing...

Thanks again.

I'm willing to bet your belt tensioner has gone bad, or your mechanic messed something up when he changed it for you. My ex's 98 cav was having the same symptoms and we pinned the noise on the tensioner. Replaced and whining was taken care of. Now i know your 97 has the older 2.2 style OHV, i forgot what year the added the belt tensioner, because another girl i dated the tensioner was actually the idler pully on her 96. Search my profile for old posts involving changing of the serpentine belt because i made a huge write up on it for the OHV engines.

could possibly be the throw out berring in the transmission