Is this a harmonic balancer problem?
Thread Starter
Le Mans Master
Joined: Aug 2005
Posts: 6,709
Likes: 1
From: Pacific Northwest
St. Jude Donor '06
Is this a harmonic balancer problem?
I think I may have the harmonic balancer problem with my '06 coupe but am not sure. The symptoms are as follows:
I usually have a very slight high pitch sound in the engine bay at idle but not always. I also hear a similar noise when driving during low speed no load conditions (that point just between acceleration and deceleration).
The noise almost sounds more electronic than mechanical to me.
I may also have a slight wobble in the pulley but it is not severe by any means, just barely noticeable (to me anyway).
Does this sound like a harmonic balancer problem or something else? Is it worth trying to get diagnosed at this point?
I usually have a very slight high pitch sound in the engine bay at idle but not always. I also hear a similar noise when driving during low speed no load conditions (that point just between acceleration and deceleration).
The noise almost sounds more electronic than mechanical to me.
I may also have a slight wobble in the pulley but it is not severe by any means, just barely noticeable (to me anyway).
Does this sound like a harmonic balancer problem or something else? Is it worth trying to get diagnosed at this point?
Heel & Toe
Joined: Mar 2011
Posts: 24
Likes: 0
I just had the same problem. Try turning your AC on and off and see if the noise goes away when the AC is off. Mine pulley had a wobble and i am in the middle of re-assembling after installing a under drive pulley. I am hoping the noise was just the belt rubbing due to the wobble... curious to see if it is the same for you.
Burning Brakes
Joined: Nov 2006
Posts: 793
Likes: 1
It is fairly common to have some balancer wobble from the factory. I am also experiencing a noise somewhat like yours at idle and very low rpm. After reading through old posts it seems like it could possibly be the alternator. There have been people reporting the same sound coming from the alternator and when is was replaced the noise was gone.
CF Senior Member
Joined: Feb 2006
Posts: 23,313
Likes: 25
From: Tucson Arizona
Has it come loose...is the bolt tight? Is there a noticeable wobble in the pulley or belts when they're spinning?* Is there any fraying to the edges of the serpentine (or other) belts? If not I'd guess you do not have the harmonic balancer problem that affected some early VIN 2005's and certain other C6's.
*FWIW it's not ideal but a slight amount of wobble may be within 'acceptable' pararmeters.
*FWIW it's not ideal but a slight amount of wobble may be within 'acceptable' pararmeters.
Race Director
Joined: Jun 2005
Posts: 10,907
Likes: 2,699
From: Phila Suburbs 2023 C8 & 2013 650ix
What I leaned when mine was replaced is that there are no established 'acceptable' pararmeters by GM. I think part of the problem is that there is no way to measure the wobble since the engine has to be running with belt tension on the pulley for it to show the wobble.
Thread Starter
Le Mans Master
Joined: Aug 2005
Posts: 6,709
Likes: 1
From: Pacific Northwest
St. Jude Donor '06
It is fairly common to have some balancer wobble from the factory. I am also experiencing a noise somewhat like yours at idle and very low rpm. After reading through old posts it seems like it could possibly be the alternator. There have been people reporting the same sound coming from the alternator and when is was replaced the noise was gone.
When the weather clears up again and I have the car out I'll check things out in more detail and see what I can determine. The funny thing is, if this weren't the Corvette I probably wouldn't pay any attention to it.
