Serpentine belt tensioner clatter

Discussion in 'Mk5 VW Jetta, Sportwagen, and Audi A3 TDI forum' started by Rig, Jun 9, 2017.

  1. Rig

    Rig Member

    Joined:
    Jul 19, 2011
    Messages:
    60
    Car:
    2006 Jetta TDI, 1998 Jetta TDI
    Location:
    Southeast Alaska
    I'm getting a very loud tensioner clatter when I'm at a stop sign with my foot on the brake. 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.
     
  2. ncsteinb

    ncsteinb New Member

    Joined:
    Dec 11, 2013
    Messages:
    22
    Car:
    2006 BRM Jetta Manual, 2002 ALH Jetta Manual, 1997 318ti w/turbo 6cyl (M50) swap
    Location:
    Saginaw, MI
    Mods:
    Koni Yellow adjustable dampers, H&R Sport Springs, ECS Tuning Dogbone insert, ECS Single Mass Flywheel (both), EGR delete (both), Malone tune (both), BMW-> All of the mods!
    Have you tried replacing the tensioner? Seems like there isn't enough tension on the belt, causing each power pulse to "snap" the belt tight and throw the tensioner.
     
  3. TDIJEDDA

    TDIJEDDA New Member

    Joined:
    Jun 13, 2017
    Messages:
    5
    Car:
    2006 VW Jetta
    Location:
    City of Kawartha Lakes
    It's the clutch in the main pulley, just replaced mine, make noise when first putting in drive or reverse

    Sent from my LG-H812 using Tapatalk
     
  4. gt4494

    gt4494 Active Member

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    Jan 15, 2011
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    Car:
    2005 NB
    Location:
    Southeast Coast on I-95. Radar detector on and yes Herbie still gets 40mpg at 80 mph
  5. csigona

    csigona New Member

    Joined:
    Dec 22, 2011
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    7
    Car:
    2002 Jetta TDI, 2005 Jetta TDI BRM
    Location:
    Newport, NY
    Mods:
    none
    You didn't let us know if you fixed the problem.

    I had similar symptoms and solved it by replacing the alternator clutch pulley. I bought a new one (INA brand), but I think I fixed the old one. When I took it out, it was sort of frozen, moving neither forward nor backward. It should slip in one direction and freeze in the other. I put some oil in it, threaded a big axle bolt into it and used an air wrench to get it moving. It freed up very soon and now spins good. I left the new INA pulley on the alternator and saved the original for another time.
     
  6. 2angle

    2angle New Member

    Joined:
    Sep 18, 2014
    Messages:
    7
    Car:
    2006 TDI w/ DSG
    Location:
    NJ
    Mods:
    None
    Same problem here. Alt pulley (#022 903 119) was the source of my noise too. I did not have to replace the tensioner.
     
  7. Passat Fahrer

    Passat Fahrer Member

    Joined:
    Apr 5, 2015
    Messages:
    35
    Car:
    VW Passat TDI 2.0 2005
    Location:
    Germany
    I'm having the same exact problem with my Euro BGW 2.0 TDI PD engine with a 6 speed manual transmission. Belt chatters between the alternator and the power steering pump pulley violently in idle also in neutral. Also the belt squeals like a bat out of hell when turning the steering wheel lock to lock. The engine is extremely louder since this problem started as well. A week ago I started the engine up was around 40 degrees and my alternator warning light came on in the center dash display, flashed on and off several times, checked for charging and it was, battery voltage was also optimal. Revved the engine in neutral at a stop light and the lamp went out and hasn't come on since. I bought a new Alternator dynamic pulley from INA since they manufacture them for VW anyways. Just waiting on my tools to come from Hazet, they were on back order until next week.
     

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