hockey.rulez

I have a 2011 C6 with 46,000 miles on it. I've had a squeak/chirp after a cold start that persists for about 3-5 minutes then goes away. It's been going for the last 4,0000-6,000 miles. I've had the serpentine belt replaced, it didn't stop the squeak/chirp. Then I had a tensioner replaced, the squeak/chirp still occurs. Does that sound like the harmonic balancer? Thanks!

GuyFromLeMans

Yes it does sound like the HB. Check for wobble.
And don't feel bad about creating thread # 1019 on the HB going bad... some will STILL tell you that there is nothing systematically wrong with the GM HB.

If you see a wobble on it, throw that piece of garbage in the trash, and install a REAL HB (ATI or Powerbond).
Worth the piece of mind, and I speak from experience looking at my ATI spin true and quiet, after having heard the squealing pig under the hood on cold starts (with the GM trash).

(Or listen to the ones that will tell you there is nothing wrong with a little wobble on the HB, and sing along the chirping birds when you start your car, keeping fingers crossed that the damn thing will not come apart under the hood while spinning at a few thousand RPM)

Good luck!

Mike's LS3

I had a cold startup belt chirp that progressively worsen. Changing the belt temporarily stopped it. Installed an ATI and it's gone. My oem HB always had a slight wobble, but needed replacement after 64k miles.

Do this first before replacing the HB.

1. Replace belt - Done.

2. Make sure all your pulleys are good before replacing the HB. Wiggle them/ move them back and forth and check for excessive play.

3. Check to see if the edge of your belt shows irregular wear.

4. Replace HB with ATI or a quality aftermarket HB.

Not So Fast

Out of curiosity has GM ever addressed this seemingly large problem??
Mine seems good for now but makes me worry what with all of these threads on how bad the GM HB is.
NSF

GuyFromLeMans

Two reasons:
1- Too costly for GM to even consider addressing (at around $1000 a pop)
2- Not life threatening, therefore little or no fear of a class action suit.

Bottom line: Not within the "customer satisfaction" program budget....

windyC6

LOL Lemans....a little lengthy in your persecution of the non believers, but you are spot on. You would think with all the threads created on the subject that Corvette Nation would come to terms with the fact that these things are just a major factory @#$%-up, but alias here we have another thread. Mines been wobbling about the same now for about 5 years but its gotten no worse. I don't track the car or drive it overly hard to extremes so I'm just keeping an eye on it. Not so much that the $1,200 bucs to have it fixed isn't bad enough, but I just don't want some shop to get in there and muck something else up while they are fixing it if you catch my drift.

GuyFromLeMans

I always had very little tolerance for deniers and/or revisionists (not a matter of faith here, only facts)....

Not So Fast

So they don't replace even if your car is under warranty huh? Silly question I guess since we all know about the $1.87 ignition part that as killed people and they still haven't addressed to my knowledge
NSF

hockey.rulez

Thanks for all the replies! I really didn't want to start a new thread on this topic but there seem to be some difference in opinions on this topic. My HB seems to have a little wobble, so after reading lots of other threads, I assumed that the HB was the problem but wanted to make sure. I was hoping it was something easier because I too hate the idea of part of my car being taken apart and put back together and have something else screwed up by the shop along the way.

So it seem like an aftermarket HB is the way to go. I saw ATI as a suggestion. Any other suggestions? I'll also read other threads but curious if any other HBs are also known to be good quality.

Now I hope that the labor is covered by my extended warranty!

windyC6

Now you open up a new can Hockey. Some dealers won't install non GM parts under warranty. And that's if your particular warranty even covers the balancer. Obviously an after market balancer is the best way to go, but if your warranty does cover it but only if you go with another GM part then you have to make the decision of forking out the $$$ for an aftermarket job....or trying another GM part for free to see if it maybe works better this time around. either way....good luck.

GuyFromLeMans

Most definitely!
In this thread: https://www.corvetteforum.com/forums...-balancer.html (the most recent one on HB failure until yours), member "Hells" is mentioning having replaced his HB with the GM part, not once, but twice!!!.... to have them all fail, one after the other (yes, that is THREE GM balancers go bad on the same car!!), and finally installed a Powerbond, which ended his (and the car's) suffering.

Should be enough evidence.

HBsurfer

I think a lot of the confusion on this is because some owners are willing to "keep an eye on it" while it is clearly wobbling. Some have said that a little wobble is fine as long as it does not get worse. No other car that I own now or have owned in the past has had a balancer that wobbled at all. The ATI balancer that is on my Corvette now does not wobble at all. I did not buy a Corvette to "keep an eye on" a marginal part, which this clearly is. Would anybody here "keep an eye on" a wobbling alternator or water pump pulley? Maybe so, but not me. ATI and Powerbond are excellent replacements. I am sure there are others as well.

windyC6

Good points surfer....but for over 45 years I have maintained and worked on all my cars and that includes all my high performance cars from back in the day of real street racing as unsafe as it may have been. I watched many a wobbling pulleys from water pumps to alternators and A/C units...etc...etc. Just cause they wobbled slightly does not mean that the end of the world is near. While most balancers do run fairly true, its not uncommon at all for some to have a slight wobble to them and this is no issue. Our 2008 Silverado has a slight wobble to it. My friends GT Rustang has a slight wobble to it. Now this is not to say that GM doesn't have a balancer problem with their Corvettes....they surely do. I guess what matters here is ones definition of "Slight" and ones experience on when a wobble is too much. And absolutely i'll be watching my balancer to see if the wobble gets worse or stays about the same. And i'll tell ya right now if it doesn't get any worse there ain't no way I'm forking out $1,200 for a replacement.

bucwheat

My dealer replaced mine on a recall at no chatge.

Starfish Prime

My 2011 with 20k miles had exact same symptoms. Dealer replaced HB under power train warranty. I have never had a bad HB in any other car I ever owned. I had 4 other various LS cars also. Your fuel pump will be next . Mine is. I'll be doing that nightmare myself. Dealer wants 1700. Good luck OP.

Charlie in TX

I didn't replace mine because it wobbled. I replaced mine because of the crickets under the hood. At first they went away before I left the garage. In the end, took several minutes/miles to go away. When I had the ATI installed, it smashed the crickets for good.

Hells

I just had a Powerbond underdrive pulley installed 2 days ago. No more chirping after 3 GM harmonic balancers.

GuyFromLeMans

When did GM issue a recall on the HB???? Slip of the tongue maybe?

HBsurfer

There was a TSB for the HB bolt. Never was a recall for the harmonic balancer

GuyFromLeMans

Thank you for setting the record straight.