Serpentine belt/tensioner clatter

[Rig]

In my 2006 jetta, I'm getting a very loud tensioner clatter when I'm at a stop sign in Drive with my foot on the brake (DSG transmission). I've tried to pinpoint the noise with a stethoscope, and it seems to be coming from underneath the tensioner wheel.

When I park the car with the parking brake on, and run it in Drive or Reverse, the clatter begins. It's louder by far than the engine. I can observe the serpentine belt vibrating wildly and perhaps slapping the pulleys.

When I put the car in Neutral or Park, the clatter goes away immediately, and the serpentine belt runs smoothly around the pulleys.

I'm suspicious of the alternator clutch pulley (though it feels okay) and the tensioner itself. What else in the belt drive area could make such a racket? It happens ONLY at low RPM, with the engine loaded.

By the way, I just put in a new dual mass flywheel, which has helped the shudder a lot and removed some of the general noise, but did not affect this tensioner clatter, which is getting worse. I once thought the clatter had to do with the DMF going bad, but the DMF had a different contribution to the vibes.

 

[Marinel]

Still sounds like the alternator pulley. The best way is to release the belt tension and check to see if it's seized. On a brm jetta all you need is a 17mm open end wrench to release the tension.

 

[N.CaTDI]

Still sounds like the alternator pulley. The best way is to release the belt tension and check to see if it's seized. On a brm jetta all you need is a 17mm open end wrench to release the tension.

Yes and you can start the car with the belt off to see if the noise is gone then you know if you are at the right place. My alternator pulley broke off the shaft just pulled the belt out of the way and drove it home about 3 miles.

 

[firehawk618]

He said the alternator pulley felt fine.

I would still pull the serpentine belt off and make sure the noise is gone.

Could be coming from your timing belt or related components.

 

[Kwotattoo]

Do all of the 06 Jetta TDI have the over run alt pulley? I went to change my wife's and it was a solid pulley so I need a different tool, but will the over run still go on to replace the solid pulley?

 

[Henrick]

All of them have ther overrunning pulley.
You are mistaken or don't know how to check it (or have a crappy aftermarket alternator installed).

 

[kbaisley]

Do all of the 06 Jetta TDI have the over run alt pulley? I went to change my wife's and it was a solid pulley so I need a different tool, but will the over run still go on to replace the solid pulley?

It could be that your pulley locked up. All of the 06's have a clutched pulley.

 

[6PackCharlie]

My 2006 tension pulley was making quite a bit of noise at 117k. I had it replaced.

 

[craig01b]

Yup, alternator pulley...... remove belt and spin it...it should only spin one way. If it goes both ways, the belt will bounce.... a lot!

 

[b1mmuo27]

My daughters 06 made a racket since she had it. Just changed the timing belt, water pump, tensioner. When I put a new serpintine belt on it was jumping all over the place. Took the belt off no noise. Replaced the tensioner no belt jump or noise.