1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

04 1.8T engine management light on! Advice please

Discussion in 'A4/A4 cabriolet/S4 forum(B6 chassis)' started by Ratha, Dec 1, 2010.

  1. Ratha
    Offline

    Ratha New Member

    Joined:
    Nov 29, 2010
    Messages:
    4
    Likes Received:
    0
    [Dec 1, 2010]
    My girlfirend has a 1.8T 04 plate A4 cab. she started it the other day and the engine management light came on and it started to run lumpy, as in sounding like it was a cylinder down. I have checked the core/coil plugs and found that the number 1 cylinder wasnt working. i have replaced with a genuine VAG part and it has sorted the issue, as in all of the cylinders appear now to be working and when you remove all of the the core plugs you can see it sparking and hear them clicking etc. however it is still running very lumpy when idling. It appears to cure when you give it some revs partly. Any ideas?
    #1
  2. Ads

    Ads

    [Oct 20, 2014]

  3. AU01 A4
    Offline

    AU01 A4 Member

    Joined:
    Jan 2, 2009
    Messages:
    211
    Likes Received:
    0
    [Dec 1, 2010]
    Crank Brather vale there a lot of threads on here about it
    #2
  4. AU01 A4
    Offline

    AU01 A4 Member

    Joined:
    Jan 2, 2009
    Messages:
    211
    Likes Received:
    0
    [Dec 1, 2010]
    #3
  5. Ratha
    Offline

    Ratha New Member

    Joined:
    Nov 29, 2010
    Messages:
    4
    Likes Received:
    0
    [Dec 1, 2010]
    cheers, gives me a place to start looking. I'll get it scanned.
    #4
  6. pj123
    Offline

    pj123 Member

    Joined:
    Oct 5, 2010
    Messages:
    295
    Likes Received:
    9
    [Dec 1, 2010]
    Poor idle can be from any of the following:

    MAF, Ignition Coil, Spark Plug, VAC Leak, O2 Sensor, Throttle Body or Temp sender.

    Cleaning the TB is a cheap an easy place to start.
    Unplugging the MAF tests if the MAF is faulty
    Temp sender / o2 sensor you'll need to do a scan.
    Vac leak, look for split hoses or data logging using vag com

    Not sure if the 3 older coil packs are weaker in any way and could make a difference?
    #5
  7. CHRIS555
    Offline

    CHRIS555 DOPE with added OCD

    Joined:
    Jul 4, 2010
    Messages:
    1,941
    Likes Received:
    2
    [Dec 1, 2010]
    Crankcase breather valve for sure - let ne kniw if you need the part numbers etc, its a £6 part and a DIY job
    #6
  8. itsmeagain
    Offline

    itsmeagain 1.8T Sport Cabriolet

    Joined:
    Mar 6, 2010
    Messages:
    439
    Likes Received:
    0
    [Dec 2, 2010]
    I had the same problem on my cab, I replaced the valve and it cured the problem. Easy job to do
    #7

Share This Page