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Alternator pulley seizing !

Discussion in 'A4/A4 cabriolet/S4 forum(B6 chassis)' started by markpw73, Jan 7, 2009.

  1. markpw73
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    markpw73 Member

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    [Jan 7, 2009]
    Hi,
    Had my A4 avant 1.9tdi 130se for a month now and just had the rear isofix bars retrofitted by my local dealer (Vindis Audi Bedford) and they did the usual winter health check for free which it passed with flying colours.
    Although the tech did mention my alternator pulley was seizing ever so slightly on start up!

    Is this a major worry ?

    Car is now on 107k had full Audi service history with cam belt done at 69k.

    How often does the Auxillary belt need to be changed ?

    They quoted around £250/300 for replacement

    Is it worth getting the cambelt done again at the same time ?

    Any help would be appreciated:)

    Mark:shrug:
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  3. evilscotsman
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    evilscotsman Space Cowboy

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    [Jan 7, 2009]
    Hi mate, the alternator pully is obviously bolted to the rotor shaft of the alternator itself, and has a ball-race bearing at each end. Unless it is experiencing a heavy current load, such as after starting, it is extremely free turning - unless the bearings are seizing, which would be unusual unless it was off the car and lying in the rain for weeks.

    So it is even possible that a weak battery that is drawing a lot of recharge current on a cold start could almost stop the alternator since the field is so strong on high amps - maybe you should get the battery load tested at a battery centre or kwikfit etc.

    The auxiliary belt is a good old fashioned fan belt, albeit longer etv, needs no special treatment to change it except maybe skint knuckles but not worth that kind of money! Do it yourself or get a backstreet garage to do it, its not a skilled job. The cambelt has nothing to do with the aux belt and is a pain to replace, but it is nearing 60k next year or so, maybe worth doing that now.

    If the belt is slipping its likely the tension, waterpump, or most unlikely - the alternator seizing. Check the battery and the belt tension. The belt should be pushable (deflect) towards the pulley groove direction, about 1/2 to 1" at the middle of the longest run.
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  4. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Jan 8, 2009]
    the tensioners can be known to fail, but when they do, the pulley usually starts to run at an angle and either throws the belt or shreds the belt...

    How exactly do they know the alternator is "seizing" on startup? Doesnt seem to me like something you could easily test for, unless they simply mean the belt is slipping, which as evil said may manifest itself as the alternator pulley stopping due to the load on the alternator... I'd expect it to "screech" quite loudly if that was the case though...

    If anything i'd look at changing the aux belt, i did mine myself, cost about £40ish for a new belt and tensioner iirc and took an hour or two to fit with me having no clue how to do it! Not sure if the B6 is the same, but the B5 required the lock carrier to be moved into service position, which requires removal of the front bumper. Certainly not £300quids worth of work!
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  5. markpw73
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    markpw73 Member

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    [Jan 9, 2009]
    Thanks for the feedback. It does squeel a little on cold mornings as we have had a few but only for a minute or two then is fine. I will get the battery load tested along with the tension and if necessary replace.

    Not at a main dealer though !!!
    Cheers
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  6. Munt
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    Munt New Member

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    [Jan 9, 2009]
    Hi,
    I think your alternator pulley should have a free-wheeling clutch inside it. They are designed to take out any snatch in the belt when the engine speed quickly changes from high to low, this then helps to stop the automatic tensioner from snapping.
    Last year my alternator seized, (coincidentally so had the pulley) this resulted in the tensioner mounting bolt sheering, plus a piece of the aluminum casting which the bolt screwed into snapping.
    Cheers, Munt.
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  7. scottyjohn
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    scottyjohn Member

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    [Jan 10, 2009]
    Hi,
    Yes the alternator pulley wheel has an inbuilt clutch which should only allow the wheel to turn freely one way, and this eventually starts to seize. This causes the alternator belt to jump around violently, and if you look at the front of the engine while running, the tensioner on the belt will be jumping around like crazy. You will also get bad squeaking at low speeds from the alternator.

    That was the problem with mine, and I changed the pulley wheel for about £40 and all fixed. You do need to take the front end off to get to the front of the pulley though which is a pain, jack up, undertray off, front wheels off, bumper off, and then undo front panel and it pulls forward enough to get to the pulley bolt.

    Hope this helps
    #6
  8. markpw73
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    markpw73 Member

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    [Jan 11, 2009]
    Cheers will let you know how i get on
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  9. markpw73
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    markpw73 Member

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    [Jan 13, 2009]
    Had a good look at the aux belt today with a chap who has worked with Audis for years and yes the belt is jumping slightly as the alt pulley looks to be moving to and fro with more play then usual. He seems to think the pulley has a sort of shock absorber on one side that can go and cause the pulley to move. So obviously i need to replace that pulley and the belt but as i am going to do that i might as well buy the full aux belt kit with tensioners etc.
    Any ideas on where to get OEM items at a decent price, ie, cheaper then the dealers!
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  10. markpw73
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    markpw73 Member

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    [Jan 13, 2009]
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  11. Munt
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    Munt New Member

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    [Jan 13, 2009]
    Hi Mark,
    Think you will find it is this one?
    Cheers Munt.
    http://cgi.ebay.co.uk/AUDI-A3-A4-A6-RIBBED-BELT-TENSIONER-ALSO-VW-GOLF-PASSAT_W0QQitemZ280296773686QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item280296773686&_trksid=p3286.c0.m14&_trkparms=72%3A1299|66%3A2|65%3A12|39%3A1|240%3A1318
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  12. PW-Motorsport
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    PW-Motorsport Member

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    [Jan 14, 2009]
    The alternator pulley is a common problem, changing loads at the moment. Often mis-diagnosed.

    The pulley cost £55, less than 1 hour work to change.

    You need a special tool to remove the free hub pulley.
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  13. markpw73
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    markpw73 Member

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    [Jan 15, 2009]
    Got it sorted bought the pulley £37and belt £15 from the local Audi garage so not too bad and got a friend of friend to fit for cash!!! Less then half of Audi's hourly rate before you ask.

    One thing my airbag warning light came on the other day so we hooked it up and it said something along the lines of 'drivers side airbag igniting limit reached-intermittent' It was reset and the light has been off since.

    Does this sound serious as i know Audi will charge a fortune to investigate and i know from experience airbags ain't cheap?

    Thanks
    Mark
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  14. r0nn13
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    r0nn13 New Member

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    [Feb 4, 2010]
    Hi,

    Sorry to jump on your post here, but after doing loads of searches across the net this post has caught my interest. An Audi garage has said my Alternator and Pulley are making a LOT of noise. Now this is no issue except my car is jerking at around 1500-2100 revs in most gears now. It is a 2005 B7 2.0 TDI, but most VAG parts have just evolved through the cars from what i understand.

    Can an alternator issue cause my car to jerk as i have had a bit of work done on the car already with no resolution apparent from 2 Audi Garages and 1 Indie...


    History:-

    I am having various issues with my 05 A4 2.0 TDI (BLB engine):-

    120k miles on the clock (90k done on 99% motorways)

    1. Clutch had the judder/shudder and it started to slip in most gears so I got both replaced at 115k miles.
    2. Car drove great for a few days then the engine light came on solid.
    3. Air flow meter had set it off. It was cleaned and deemed ok and error reset.
    4. Engine light came back on again, this time the air low meter sensor and the glow plug error appeared.
    5. 2x Glow plugs were replaced and the air flow meter was cleaned again and errors reset on the car.
    6. Engine light came back on again, this time the air low meter sensor and it was replaced with a new sensor.
    7. Car drove great for a few days then a new problem started and is still with the car – it is like the car is using dirty diesel, or the turbo is turning off and on as the car is accelerating and then quickly decelerating in a jerky fashion around 1800rpm in most gears now.
    8. Garage had a look at all work done (clutch/flywheel etc) and is happy work is good. Various things were checked (pipes with pin holes, leaks, fuel filter, EGR vale cleaned, throttle body, injection system) before the garage decided to take it to Audi for a check as they were stumped.
    9. Audi checked the chassis and 2 recalls were supposed to be done (ECU update for boost control and new modified pipe (not sure which one this is). Audi tech confirmed the pipe was never changed so it was changed and the ECU was refreshed/reprogrammed with the version with boost control update. Audi checked the car and confirmed all is working as it should.
    10. Car drove better than when I bought it for a few days, then the accelerate/decelerate issues is still there.
    11. It makes no difference if I have the air-con on or not, and if you drive the car a bit hard it seems to get through the issue without me feeling it. If I drive it nice and change up at 2000rpm I feel it most times.
    12. Car also has a shudder coming from the clutch at higher speeds which I was sure should be cured with the new clutch and flywheel.

    Now the air flow meter might be called an air flow mass meter and I think it is at the top of the engine area on either the right or left hand side towards the front bumper.

    Looking for help/advice here...
    #13

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