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

8L S3 limp mode but no fault codes?

Discussion in 'A3/S3 Forum (8L Chassis)' started by Craig1.8t, Jan 24, 2012.

  1. Craig1.8t

    Craig1.8t Member

    Joined:
    Dec 7, 2011
    Messages:
    108
    Likes Received:
    7
    Friend of mine has an Audi s3 1.8t and I've done a smoke test found pcv pipe split replaced that and it's still same. Clamped pipe to actuator and it boosts. Changed n75 made no difference. Any ideas?
     
  2. Google AdSense Guest Advertisement



    to hide this advert.
  3. Nilz

    Nilz Defo worth the wait :)

    Joined:
    Apr 9, 2006
    Messages:
    10,679
    Likes Received:
    597
    What are the symptoms?
     
  4. Craig1.8t

    Craig1.8t Member

    Joined:
    Dec 7, 2011
    Messages:
    108
    Likes Received:
    7
    It feels like limp mode, that's best way to describe it. Smooth just no power.
     
  5. Lewis583

    Lewis583 Active Member
    VCDS Map User

    Joined:
    Mar 15, 2010
    Messages:
    950
    Likes Received:
    89
    Done any logs? Tried unplugging the MAF?
     
  6. Craig1.8t

    Craig1.8t Member

    Joined:
    Dec 7, 2011
    Messages:
    108
    Likes Received:
    7
    Not done any logs, and can't do any till next week if I did. Maf is fairly new but tried unplugging it and still same. Pcv valve works as should too. As I said I made it run a lot better when a stopped the waste gate from opening, so must be related to that surely?
     
    #5 Craig1.8t, Jan 25, 2012
    Last edited: Jan 25, 2012
  7. Steveo_A3_1.8t

    Joined:
    Mar 26, 2009
    Messages:
    195
    Likes Received:
    3
    I read somewhere of a similar problem on an Ibiza, and it turned out the wiring to the N75 plug was faulty, maybe worth stripping back the trunking and checking it out.

    Steve
     
  8. <tuffty/>

    <tuffty/> Badger 5 Edition...Its all about the flow...
    Staff Member Moderator Audi S3

    Joined:
    Sep 14, 2008
    Messages:
    17,527
    Likes Received:
    2,110
    No, not really... the lack of boost is a symptom not a cause... all you have done is taken the ECU's control of boost and something I might say could lead to catastrophic engine failure so its not advised to fault find this way unless you are being very careful...

    Logging is the next step if you have no fault codes...

    As you have not given much info about the car at all are we to assume its mapped? what boost is it running currently? (actual boost not what you think it should run), what boost does it run with the N75 electrically disconnected? (that should also throw a fault code so don't forget to clear it)...

    Std S3's run to around 12psi normally, 3-5psi with N75 disconnected and typical up to 20/22psi mapped depending...

    <tuffty/>
     
  9. Craig1.8t

    Craig1.8t Member

    Joined:
    Dec 7, 2011
    Messages:
    108
    Likes Received:
    7
    Sorry. The car is fully standard. Brand new engine last year. According to measured values the boost matched specified. I put the pipe back as normal and stopped boosting once the boost came in.
     
  10. quattros3

    quattros3 New Member

    Joined:
    Mar 13, 2014
    Messages:
    1
    Likes Received:
    0
    Variable nozzle turbo. Sticking vanes!!
     
  11. Alex C

    Alex C Well-Known Member
    VCDS Map User

    Joined:
    Jan 26, 2010
    Messages:
    2,924
    Likes Received:
    230
    not in a petrol motor, diesel maybe, but not a 1.8T. Petrol engines get too hot for a variable geometry turbo
     

Share This Page