2006 Pulley???

[Gary B.]

Is there still a problem with one of the Pulleys on the C6s like there was on some of the C5s.
It sounds like a noisy lifter when under power when the engine is cold.
Is there a letter to dealers on the fix?

[Terry M.]

Re: 2006 Pulley???

Gary,
I think early C6s had problems with the harmonic balancer. You might want to search over of the Corvette Forum in the C6 General section. I think I saw some postings over there about it.

[Tom H.]

Re: 2006 Pulley???

Here's a bulleting I found that I had not seen before. Might be worth a look if your car is equipped with the cooler. I have the whole bulletin I can email you.

#PIC4912A: Buzz Or Rattle Noise From Under Vehicle While Accelerating 2500-3500 RPM - keywords accelerate acceleration clamp cooler creak drive-shaft fluid housing itching line manual noise normal operating pipe - (Jan 28, 2009)

Subject:Buzz or Rattle Noise From Under Vehicle While Accelerating 2500-3500 rpm

Models:2005-2008 Corvette - Equipped With Transmission Cooler Only.

This PI was superseded to update keywords. Please discard PIC4912.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
<A href="#ss1-2229025">Condition/Concern:

Some customers may comment of a buzz or rattle noise from under the vehicle. Noise typically will occur between 2500-3500 rpms, engine at normal operating temps. Noise is noticed more when traveling up an incline while turning left or right. This may be the result of a transmission cooler line that fits loose in its retaining clamps on the torque tube. This line may vibrate with engine harmonics and rattle against the retaining clamps causing this noise.
<A href="#ss2-2229025">Recommendation/Instructions:

[Gary B.]

Re: 2006 Pulley???

Thanks Terry and Tom.
It sounds more like timing or a lifter. I was talking to a couple of guys yesterday who have C5s and C6s and they mentioned that if you open the hood and someone controls the throttle you can see, I think the "idler pully" wobble slightly when engine is cold.

[Terry M.]

Re: 2006 Pulley???

I can't say I have heard that about the idler pulley, but on my Z06 one of the idler pulleys (actually one of the tensioner pulleys) is right on top of everything in a very high visibility area. I believe there is an idler pulley (non-adjustable) farther down on the accessory drive system, but it is all but invisible. When I changed the serpentine belts (a detestable job on a C6) I had to work the belt around that pulley by Braille. Next Spring I'll try to remember to take a look at the tensioner pulley.

The LS2 or LS3 may have a different belt arrangement -- so my experiences may be apples to your oranges.

The complaints I was recalling involved the harmonic balancer coming apart on early C6s, but it sounds like that is not the issue you are encountering.

[Clem Z.]

Re: 2006 Pulley???

I can't say I have heard that about the idler pulley, but on my Z06 one of the idler pulleys (actually one of the tensioner pulleys) is right on top of everything in a very high visibility area. I believe there is an idler pulley (non-adjustable) farther down on the accessory drive system, but it is all but invisible. When I changed the serpentine belts (a detestable job on a C6) I had to work the belt around that pulley by Braille. Next Spring I'll try to remember to take a look at the tensioner pulley.

The LS2 or LS3 may have a different belt arrangement -- so my experiences may be apples to your oranges.

The complaints I was recalling involved the harmonic balancer coming apart on early C6s, but it sounds like that is not the issue you are encountering.

i think the C-6 damper problem was it would spin on the crank snout because there is no key and this would loosen the bolt allowing the damper to move forward. the fix was a diamond impregnated washer went on the crank snout before installing the damper and a new damper bolt.

[Tom H.]

Re: 2006 Pulley???

We did a few repairs to correct the damper issue a few years ago. It will not give the sound symptom you are hearing though.