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A4 B6 Common Faults / Buying Checklist

pj123 Dec 7, 2010

  1. pj123

    pj123 Member

    Thought I'd start a thread for common faults and things to look out for when buying an A4. Feel free to add to the list, my list only covers the 1.9 Tdi.

    My car is Audi A4 B6 1.9 TDI PD 130, AWX - 8 years old, 103k

    -Common Fault

    Plenum Chamber Grommets
    -Plenum Chamber grommets block with silt allowing water to fill the plenum chamber infront of the windscreen. Causes flooding into passenger footwell, ECU, HVAC fan, brake servo.
    -Remove grommets by removing battery and battery tray.

    Wiper mechanism seizing
    -The mechanism that links the motor to the wiper arms can seize up
    -Remove mechanism and regrease all moving parts

    Air con regas
    -Airconditioning system slowly leaks and requires regular regas. Pump fails to operate below a certain gas pressure.
    -Regas every couple of years.

    Brake Light Switch
    -Traction control light comes on when brake pedal is first pressed
    -Replace Brake light Switch

    Airbag connector below seat
    -Airbag connectors below driver or passenger seat cause airbag light to come on
    -Clean connector and add switch lubricant to connections

    Speakers crackling
    -Door connections for speaker wires were manufactured with grease in the terminals which breaks down and causes speakers to fail & crackle
    -Remove grease from door connectors

    Rear washer jets block
    -Rear washer jets block causing washer pipe failure and corrosion within tailgate
    -Keep jets clean

    Glovebox hinges
    -The soft close damper/ glovebox light switch unit becomes stiff putting unnecessary stress on the glovebox hinges
    -Remove plastic cover on the side of the glovebox and lubricate light switch plunger

    Worn fuel line
    -On 1.9 TDI -The fuel line rubs on the underside of the air intake pipe that goes into the EGR valve. Wear occurs because braided protection slides further down the fuel line exposing the rubber.
    -Reposition braided protection on fuel line and secure with zip tie/ jubilee clip

    HVAC failure
    -There are small servos that control the HVAC system which are prone to failure. Motors show signs of failure when the start to 'click'. Defroster flap commonly first to fail. Remove glovebox to access 4 servos including defroster flap.
    -Replace servo or disconnect whilst open.

    Coolant Temperature Sensor
    -Prone to failure and throw an intermittent fault code
    -Replace coolant sensor

    -Prone to fail overtime and engine can no longer remain at 90 degrees during use. Engine takes a long time to warm up.
    -Replace thermostat

    Battery failure
    -First signs of the battery failing is a brake warning light on the DIS followed by 3 beeps. First occurs during cold weather. A good battery should hold 12.6v, weak battery will be 12.2v or less.
    -Replace battery

    Rear Anti roll bars
    -Anti roll bars corrode, crack the plastic collar which then damages the rubber bush.
    -Replace anti roll bar and rubber bushes

    Wiper blades
    -Clips securing the wiper blade to the arm break. Also plastic hinge piece prone to wear allowing deflector blade to touch & scratch the windscreen.
    -Replace entire wiper arm as clips are not available separately.
  2. simon.m

    simon.m Active Member

    thats not a bad list really could be a lot worse lol
  3. iyrix

    iyrix Member

    Good write up there. They all seem to be the common points.

    That speaker crackling is a funny one, sometimes my speakers in the door go off. Turn it up and they come back on. Never really worried too much, just a pain sometimes.

    Im also going to look into as the "Plenum Chamber Grommets" i've never done this..


  4. Funkyfin2000

    Funkyfin2000 Member

    Grreat list!

    I tell you what would be good with it, some guides on how to sort.

    Thank you tho!
  5. jamoA4

    jamoA4 New Member

    I get the same thing with the door speakers in the front, same as iyrix, turn the volume up and they come back on. I just assumed that they were blown and needed replacing or maybe a loose connection.
  6. quattrojames

    quattrojames Moderator Staff Member Moderator Audi A6 Audi Avant Owner Group

    The speakers crackling is more likely to be a degradation of the wires in the rubber sleeves in the door shuts as the doors keep being opened and closed.

    Also for the rear wiper, a common issue is for the pipe to split where it flex's at the tailgate hinge point.
  7. silversurfer

    silversurfer Member

    Is the catch/clip snapping on the lid of the front centre arm rest a common fault ?
  8. Funkyfin2000

    Funkyfin2000 Member

    I reckon so, could someone tell me the part number i need to get it fixed? Its got a leather black top to the lid.
  9. silversurfer

    silversurfer Member

    If you replace the rear anti roll bar it would be worth upgrading to an RS4 one for a few extra £'s

    Parts required:

    RS4 'DRC' 22mm Rear Anti Roll Bar -- 8E0511409AM
    Bushes -------------------------------------- 8E0511327B (X2)
    Bolts for Brackets ------------------------- N10127706 (X4)
    Bolts for ARB links ------------------------ N10528101 (X2)

    Loads of good info though PJ123 :) :applaus:
    Last edited: Dec 14, 2010
  10. Funkyfin2000

    Funkyfin2000 Member

    any idea on cost for that?
  11. silversurfer

    silversurfer Member

  12. GaryAD

    GaryAD New Member

    Good post many thanks!

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