Serpentine belt / tensioner chatter

[Curious George]

Since I bought my '99 C5 (in August late '07) it has had a "chatter" from the serpentine belt / tensioner. Here is the scenario: Start car (A4), when you put it in Drive, you hear the belt / tensioner chatter for a moment, then it goes away. If you happen to turn the steering wheel left or right (immediately after putting the car in Drive), the noise is slightly worse, then goes away. With the hood up, and car running, you can actually see the serpentine belt and tensioner chattering under the above conditions. After the car warms up to operating temp., it is not so bad, but it is still noticeable.

I replaced the tensioner pulley and tensioner itself, no change. New serpentine belt, no change. New A/C belt, no change. A/C tensioner / pulley appear to be OK. The harmonic balancer separated awhile back and was replaced, but the chatter still prevails. Power steering pump appears to be OK, no leaks, etc.

Any ideas what could be causing this because it is driving me CRAZY! I've been driving my C4 more since I cannot stand it... poor old girl.

CG

 

[Curious George]

No ideas guys?

CG

 

[StewB66]

Hi. Just saw your thread. Had the same problem with my '98 when I bought it. The guy who owned it previously had chased this problem a half dozen times, always with GM replacement serpentine belt.

I (on advice of actual users) bought a Goodyear 4060802 serpentine belt at Autozone (I think it was called Gatorback or some such name). I also replaced the idler pulley at the same time = problem solved!

Hope this helps!

 

[Hib Halverson]

Some movement of the tensioner is normal...afterall, it's "tensioning" the belt, however, excessive chattering is not normal.

I'd make sure the replacement tensioner is the correct unit for the vehicle...if it was a low-cost OE replacement from a mass-marketer, it might be a quality issue or that it's not the right tensioner for the engine.

IMO, the only good ones to use are either stock GM or Goodyear.

As for belts, the way to go is either stock GM or the Goodyear Gatorback belt discussed earlier.

 

[VETTEX2]

there are 4 idler pulleys
any one of them can cause a chatter
I would not waste money on a tensioner when it's the pulleys that go bad 9 times outs 10

 

[Pac-man]

There is a tsb on this issue. I had it fixed accordingly years ago. I had to bring the tsb that I printed out myself to the dealer. The bolts on the tensioner need to be torqued to a specific poundage or something warps and creates the noise. The tech can't use an air tool, must use a hand held torque wrench. Also GM redesign the part that was warping and that needs to be installed as well. This was years ago and this is the best I can recollect but the noise drove me nuts and I finally did the research and found the solution. Not many people, even dealerships know about it.

 

[wascapsfan]

There is a tsb on this issue. I had it fixed accordingly years ago. I had to bring the tsb that I printed out myself to the dealer. The bolts on the tensioner need to be torqued to a specific poundage or something warps and creates the noise. The tech can't use an air tool, must use a hand held torque wrench. Also GM redesign the part that was warping and that needs to be installed as well. This was years ago and this is the best I can recollect but the noise drove me nuts and I finally did the research and found the solution. Not many people, even dealerships know about it.

What was the TSB?? If the dealers don't know about it then how do they know to fix it?? I hate my local dealership because they don't care about anything that doesn't make them money. Any info would be great.
Thanks

 

[Pac-man]

Technical Service Bulletin. The auto manufacturers issue them in lieu of a recall. I actually found it here at the CAC somewhere. Print it out and bring it to the dealership. Everything is explained on the TSB.

 

[Bobsvette]

For what it's worth I had the same exact problem on my 99, went to a local gm dealer otfl and what it boiled down to was rust that had built up on the edges of the pully's, belt's were fine but got replaced anyway and pully's cleaned up.. quiet as a mouse! P.S. no slipsumeasy used at all on belts

 

[Curious George]

For what it's worth I had the same exact problem on my 99, went to a local gm dealer otfl and what it boiled down to was rust that had built up on the edges of the pully's, belt's were fine but got replaced anyway and pully's cleaned up.. quiet as a mouse! P.S. no slipsumeasy used at all on belts

Can anybody explain how rust on the edges of the pulley's would cause "chattering"?

Not trying to be smart, just trying to understand.

CG

 

[XLR8]

What was the TSB?? .............. Any info would be great.
Thanks

Technical Service Bulletin. The auto manufacturers issue them in lieu of a recall. I actually found it here at the CAC somewhere. Print it out and bring it to the dealership. Everything is explained on the TSB.

Check out the Corvette Action Center | Tech Center

and specifically the Corvette Action Center | Tech Center | Knowledgebase

Jane Ann

 

[Bobsvette]

Believe me i was trying to make sense of it but that's what the guy behind the counter told me. at that point all i knew was that the engine compartment was super quiet again, hell he could of raked me over the coals with any other explanation ,You go to a dealership and your really at there mercy.I feel I was treated fair.

 

[c4c5specialist]

HI there,

#1, automatics had a TSB for chatter due to the low rpm that those run at, usually 550-650 rpm.

#2, GM TSB 99.06.04.029A covers this and says the following
Condition::

Some customers may comment on an intermittent accessory drive rumble noise when performing a garage shift and/or during parking lot maneuvers, such as turning the steering wheel to the lock position. This noise may also occur when turning on the air conditioning at idle conditions.

Cause::

Engine idle speed may drop below 600 RPM while performing a garage shift, turning the steering wheel to the lock position, or turning on the air conditioning. This noise may be amplified by a large rate of change in engine RPM. This condition can also be aggravated by different low engine RPM driving conditions.

Correction::

A new Generator with Decoupler Pulley and reduced damping Accessory Drive Tensioner was implemented for all Corvettes with automatic transmissions at 2001 SOP (Start Of Production). The generator with decoupler pulley is used only on Corvettes equipped with an automatic transmission.


Also, there is a calibration update for the PCM to assist with idle stability.

Allthebest, c4c5

 

[Curious George]

HI there,

#1, automatics had a TSB for chatter due to the low rpm that those run at, usually 550-650 rpm.

#2, GM TSB 99.06.04.029A covers this and says the following
Condition::

Some customers may comment on an intermittent accessory drive rumble noise when performing a garage shift and/or during parking lot maneuvers, such as turning the steering wheel to the lock position. This noise may also occur when turning on the air conditioning at idle conditions.

Cause::

Engine idle speed may drop below 600 RPM while performing a garage shift, turning the steering wheel to the lock position, or turning on the air conditioning. This noise may be amplified by a large rate of change in engine RPM. This condition can also be aggravated by different low engine RPM driving conditions.

Correction::

A new Generator with Decoupler Pulley and reduced damping Accessory Drive Tensioner was implemented for all Corvettes with automatic transmissions at 2001 SOP (Start Of Production). The generator with decoupler pulley is used only on Corvettes equipped with an automatic transmission.


Also, there is a calibration update for the PCM to assist with idle stability.

Allthebest, c4c5

Now all that makes sense to me.

CG

 

[Toms007]

Paul comes through once again!

 

[WB6HRO]

You might also look to see if the harmonic balancer is tracking straight. When the dampener material deteriorates the pulely wobbles.

 

[bighank]

Go for a new IDLER pulley dealer replaced everything else and still had squeel

Dealer replaced tensioners, belts and even the water pump but still had intermittent squeal. Got an idler for $16 from Pep Boys and replaced it myself. No more squeal. Corvette specialist dealer was clueless to the TSB. Old style pulleys had a dust shield that is different from current idlers. I had to add a small washer in addition to the "dust shield" washer which is in front of the pulley to prevent the new pulley from seizing against the mounting stud. Don't discard the original dust shield just add a washer. GM wants over $50 for a $15 part. Worst part was reinstalling belt. Very tight but it can be done.

 

[Pac-man]

if I recall correctly it was the dust shield that warped and caused the noise if not torqued properly and caused the noise. Makes sense. There is a TSB out there though.

 

[bighank]

Mine had lost a LOT of grease

if I recall correctly it was the dust shield that warped and caused the noise if not torqued properly and caused the noise. Makes sense. There is a TSB out there though.

When I pulled mine I could see where the grease had flown out of the bearing. Cleaned dust shield with solvent and used it with new pulley.
Some people say to relubricate the pulley. BS. It will throw out the grease and you will be wasting time when a $16 dollar part fixes the problem for another 50K or 60K miles.

 

[Curious George]

When I pulled mine I could see where the grease had flown out of the bearing. Cleaned dust shield with solvent and used it with new pulley.
Some people say to relubricate the pulley. BS. It will throw out the grease and you will be wasting time when a $16 dollar part fixes the problem for another 50K or 60K miles.

All the tensioners I have looked at have been in the $49~$55 range. Nothing for $16 dollars for a C5.

CG