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

Surging on boost

Discussion in 'A3/S3 Forum (8L Chassis)' started by s4mark, Aug 2, 2010.

  1. s4mark
    Offline

    s4mark Member

    Joined:
    Apr 27, 2007
    Messages:
    236
    Likes Received:
    1
    Hi all. Just after some advice really.
    Have noticed todal that my s3 seems to be surging when boosting. It seems fine up to around 2500rpm but then seems to be very rough in its power delivery, almost a flat spot and then it seems to kick in again at about 4000rpm but varies. Also seems very jerky when I come on and off the throttle. Could this be the DV at fault? I have been told that the standard DV's are noisy if they are shot, but mine is still silent. Checked it on diagnostic equpiment at work (not Vagcom) and it didnt show any fault codes.
    Any pointers in where to look first? Can't seem to see any split hoses as far as I can see. Am thinking of doing the N249 bypass mod soon but would like to get this sorted first.

    Cheers chaps

    btw car is unmodified 210 AMK
    #1
  2. s3_kev
    Offline

    s3_kev Stage2'd!!!!!!

    Joined:
    Feb 17, 2008
    Messages:
    1,999
    Likes Received:
    1
    i had similar faults when on stage one mapping, then had stage2 put on and the only other thing changed at the time was the vacum pipes and crankcase breather pipe under the inlet manifold were split so changed them problems gone ever since, i doubt it was the mapping that changed things probably the boost leak, check these hoses as could be due to boost leak??
    #2
  3. s4mark
    Offline

    s4mark Member

    Joined:
    Apr 27, 2007
    Messages:
    236
    Likes Received:
    1
    cheers mate gonna get my hands dirty tomorrow at lunchtime, started thinking MAF as I remember my A4 1.T which was revo'd suffered from surging and that was all down to the MAF but cant remember it being jerky like this is
    #3
  4. s3dave
    Offline

    s3dave TFSI Hybrid

    Joined:
    Nov 11, 2009
    Messages:
    10,120
    Likes Received:
    11
    my maf sorted my surging out....
    #4
  5. s3_kev
    Offline

    s3_kev Stage2'd!!!!!!

    Joined:
    Feb 17, 2008
    Messages:
    1,999
    Likes Received:
    1
    you could try unplugging the maf and see if the issue goes away.
    #5
  6. s4mark
    Offline

    s4mark Member

    Joined:
    Apr 27, 2007
    Messages:
    236
    Likes Received:
    1
    Seem to remember it being about £100 last time for a new MAF if I exchanged the old unit. Wonder if its still the same?
    #6
  7. s4mark
    Offline

    s4mark Member

    Joined:
    Apr 27, 2007
    Messages:
    236
    Likes Received:
    1
    have been looking at the hoses etc today and they all look fine, no sign of splits or wear etc.
    Think i will go and get myself some vacuum hose and a t-piece and do the n249 bypass as im thinking the n249 valve may be to blame but if not then its done anyway.
    One more question, i remember a distant friend saying that they had turned their dv round? Sorry if I sound thick but do they just mean swapped the two hoses round on it? Would ask him myself but hes out of the country for a while. If this is possible are there any benefits and also will the dv still function in the same way. He seemed to reckon it made it work better but has been known to talk out of his rear lol
    #7
  8. Matt82
    Offline

    Matt82 Active Member

    Joined:
    Sep 7, 2009
    Messages:
    2,366
    Likes Received:
    0
    tbh the only times ive had surging was when i had pretty obvious boost leaks and the suring was the turbo/n75 compensating
    #8

Share This Page