I have a '97, MM6 with about 90K. Whenever I get around 2,500 - 3,000 RPM's in any gear, I start to hear a squeal. I never hear this noise when I start the car, or when it's at idle.

I've removed the AC belt, driven the car, and the squeal is still present. I've also replaced the AC belt, and AC tensione/idler pulleys. So the issue must be related to the main belt.

I've also replaced the main belt, the entire tensionser assebly, and idler pulley, but still have a squeal when driving.

Just in case I'm using the wrong terms for these parts, the items in red are the items I've replaced.


From my understanding, the noise can either be coming from the water pump, alternator, power steering pulley, or the harmonic balancer.

Not sure if this is related, but I'll mention it anyway. I've also noticed more vibrations coming through the actual shifter when the RPM's are around 3000, and the car has a slight vibration at idle.

I saw another post about marking the Harmonic Balancer. I assume I would mark a white line like the image below? If the balancer is still good, the white line should still be lined up?

 

Ill be keeping an eye on this thread. Over the winter, my 97 has also developed a similar problem but I can hear my squeal during idle. However, mine seems to be coming from either the tensioner, crank pulley, or belt itself. Hope you get yours figured out!

 

See if this thread helps troubleshoot your problems?

https://www.corvetteforum.com/forums...hat-gives.html

 

Do you know what a bad balancer wobbling looks like?

 

That's the noise mine makes but I don't see the pulley moving like that. Interesting.

 

Yes I did see this thread, but thank you for pointing me in the right direction.

 

My harmonic balancer was definitely wobbling and needed to be replaced. I replaced the factory balancer with a Powerbond balancer today, but unfortunately this didn't correct the squeal. At this point it either has to be the water pump, power steering pump, or the alternator.

It took me about 8 hours in total to replace the balancer. This including about an hour for lunch, and the time to flush/bleed the power steering system.

After replacing the balancer and flushing the power steering system, the car idles a lot smooter (almost no vibrations at idle), there is noticeably less vibrations through the shifter at higher RPM's, and the wheel turns a lot easier.


Not sure if these images will help anyone, but these are the old balancer.

 

That thing was gone, no matter what at least you got the balancer replaced before it was a real problem.

 

Just thought I'd update this thread for anyone who is following. After replacing the water pump over the weekend, the squeal is gone! Even though the harmonic balancer needed to be replaced, it was actually the water pump that was causing the noise.

I was able to replace the balancer, water pump, thermostat, overflow tank, and radiator hoses for about $350 in parts, and about ten hours of my time.

 

WOW! Excellent troubleshooting, excellent work and OUTSTANDING UP-DATE! THANK YOU!

EXCELLENT Picture documentation!

Can I use your picture/s in my picture library??

Bill

 

Thanks! I'm glad I could give back to the forum, so to speak.

Yes, please feel free to use these images. I created a share with more images from other various items, please feel free to use these as well.

https://onedrive.live.com/redir?resi...t=folder%2cjpg

Eddie

 

Mine does that. But only when it's cold. And! Only until it warms up, then it goes away. It also only does it in first & third. It's a 2003 Z..