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

Thick smoke

Discussion in 'A4/A4 cabriolet/S4 forum(B6 chassis)' started by turkonboard, Jul 11, 2012.

  1. turkonboard
    Offline

    turkonboard New Member

    Joined:
    Jul 9, 2012
    Messages:
    17
    Likes Received:
    0
    [Jul 11, 2012]
    Hey guys god I'm putting up lots of posts lol

    My Audi a4 2.5tdi each morning when I start it it doesn't start as soon as I turn the key I have to wait for it for about4-6 seconds, and then when it does start and I rev it it brings out some grey thick smoke and quite alot comes out... What may the reason be for this?
    #1
  2. Ads

    Ads

    [Sep 22, 2014]

  3. Andi25th
    Offline

    Andi25th Member

    Joined:
    May 14, 2010
    Messages:
    226
    Likes Received:
    16
    [Jul 11, 2012]
    Sounds like it needs Glow Plugs mate.

    Does it start better when its hot ?
    #2
  4. turkonboard
    Offline

    turkonboard New Member

    Joined:
    Jul 9, 2012
    Messages:
    17
    Likes Received:
    0
    [Jul 11, 2012]
    Yes deffo when the weather is ether I don't have to wait that long holding the key but still let's out a good blow of smoke
    #3
  5. bez101
    Offline

    bez101 Yorkshire & Humber Rep. Regional Rep VCDS Map User

    Joined:
    Jul 8, 2008
    Messages:
    8,811
    Likes Received:
    501
    [Jul 11, 2012]
    glow plugs
    #4
  6. Andi25th
    Offline

    Andi25th Member

    Joined:
    May 14, 2010
    Messages:
    226
    Likes Received:
    16
    [Jul 11, 2012]
    Its smoking because your having to crank it for longer fires up befor itdue to suspected faulty glow plugs.
    #5
  7. turkonboard
    Offline

    turkonboard New Member

    Joined:
    Jul 9, 2012
    Messages:
    17
    Likes Received:
    0
    [Jul 11, 2012]
    Is this a big problem or minor?
    #6
  8. Andi25th
    Offline

    Andi25th Member

    Joined:
    May 14, 2010
    Messages:
    226
    Likes Received:
    16
    [Jul 11, 2012]
    Pretty minor.
    #7
  9. Mike B
    Offline

    Mike B Member

    Joined:
    Jul 10, 2007
    Messages:
    776
    Likes Received:
    8
    [Jul 11, 2012]
    My 2.5tdi doesnt need glowplugs this time of year and will start as soon as I switch on.No need to wait for the light to go out only when its much colder.It used to be a bad starter until the cambelt was changed and it was retimed by an expert who found it was well out before
    #8
  10. swarcup
    Offline

    swarcup Well-Known Member

    Joined:
    Sep 9, 2009
    Messages:
    1,291
    Likes Received:
    37
    [Jul 11, 2012]
    sounds like pump timing aswell to me. mine will fire after a second of crank without plugs in summer everytime cold or hot. you can have the timing checked and adjusted quite easily.
    #9
  11. quattrojames
    Online

    quattrojames Moderator Staff Member Moderator

    Joined:
    Mar 28, 2008
    Messages:
    13,892
    Likes Received:
    477
    [Jul 11, 2012]
    The smoke is just unburnt fuel as the diesel is being cranked into the cylinder before it fires.

    You need to establish why it won't start, on the 2.5 it's typically glow plugs (unlikely at this time of year), a weak battery, a faulty coolant temperature sensor, or (most likely) your fuel pump timings is out.

    Glow plugs are £20 ish x 6 and a DIY job if you're competent.
    CTS is £30.
    Battery is whatever, £80 ish typically.
    Fuel pump timing is probably an hours labour for someone with VCDS.
    #10
  12. marktdisport
    Offline

    marktdisport Active Member

    Joined:
    Jul 14, 2011
    Messages:
    1,195
    Likes Received:
    15
    [Jul 11, 2012]
    id also check pump timing firstly..
    #11
  13. turkonboard
    Offline

    turkonboard New Member

    Joined:
    Jul 9, 2012
    Messages:
    17
    Likes Received:
    0
    [Jul 11, 2012]
    Wait you said battery!!! Could it be battery?? Because my window wipers at one point just got ever so weak it used to lift up n stop before getting to the end so it could come back again,, I had to keep trying every ten mins... But thankfully that's gone now
    #12
  14. marktdisport
    Offline

    marktdisport Active Member

    Joined:
    Jul 14, 2011
    Messages:
    1,195
    Likes Received:
    15
    [Jul 11, 2012]
    theres also a common issue with slow wipeers in the sticky section id say oump timing and your wipers are another issue, if the car runs the charge rate should be around 14v so plenty of power m8
    #13

Share This Page