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

possible boost issue?

Discussion in 'A3/S3/Sportback (8P Chassis)' started by c41lum, Mar 24, 2010.

  1. c41lum
    Offline

    c41lum Member

    Joined:
    Feb 11, 2010
    Messages:
    55
    Likes Received:
    0
    [Mar 24, 2010]
    i currently have a standard 59 plate S3 and for the past few days o have been wandering whether i have a boost issue or whether it was simply me becoming used to the car?

    somedays the car seems to pull well through each gear however on some occasions and i have noticed it mainly in second gear at say around 20mph and accelerating it seems like there is a lack of boost and the car doesnt start to pull until at least 3200 - 3400rpm

    being new to the car i was unsure if i was imagining things or not so i thought i would ask the experts, im currently offshore but i intend checking the Diverter valve for any splits and getting the car vagcom'd once i return to dry land.

    any help or advice is appreciated

    cheers
    Callum
    #1
  2. Ads

    Ads

    [Oct 23, 2014]

  3. c41lum
    Offline

    c41lum Member

    Joined:
    Feb 11, 2010
    Messages:
    55
    Likes Received:
    0
  4. dc240969
    Offline

    dc240969 Member

    Joined:
    Oct 12, 2008
    Messages:
    887
    Likes Received:
    0
    [Mar 28, 2010]
    For a car your age, without doing anything to it yourself, take it to the dealers.
    #3
  5. Boydie
    Offline

    Boydie Boycie VCDS Map User

    Joined:
    Dec 24, 2006
    Messages:
    2,852
    Likes Received:
    194
    [Mar 29, 2010]
    Ditto but how many miles are on the car? can't be that much if you are off shore regularly :S
    #4
  6. warren_S5
    Online

    warren_S5 Moderator Staff Member Moderator VCDS Map User

    Joined:
    Oct 31, 2007
    Messages:
    7,178
    Likes Received:
    2,369
    [Mar 29, 2010]
    Your car should have the new revision D boost gauge, so no rubbers to split in those.

    Boost control valve N75 could be at fault. May also be worth unplugging the MAF and seeing if it runs any differently.

    I'm not sure where the turbo's kick in on these cars; can't be much below 3,000rpm (anyone know?)
    #5
  7. S.
    Offline

    S. Well-Known Member

    Joined:
    Mar 5, 2009
    Messages:
    1,464
    Likes Received:
    220
    [Mar 29, 2010]
    2500rpm. i think you're getting used to the car.
    #6
  8. c41lum
    Offline

    c41lum Member

    Joined:
    Feb 11, 2010
    Messages:
    55
    Likes Received:
    0
    [Mar 29, 2010]
    im on a 2 on 3 off rota so the car is used quite frequently during the 3 weeks at home, milage is around 2.5k if i remember correctly
    #7
  9. c41lum
    Offline

    c41lum Member

    Joined:
    Feb 11, 2010
    Messages:
    55
    Likes Received:
    0
    [Mar 29, 2010]
    @warren, thanks i will try these once i get home next week,

    @s. thats a possibility mate, if so then happy days but i would still like to investigate all posibilities just to make sure and put my mind at rest :icon_thumright:
    #8
  10. KRL
    Offline

    KRL Member

    Joined:
    Jul 13, 2007
    Messages:
    522
    Likes Received:
    1
    [Mar 29, 2010]
    All you need to do to check if you have a boost leak is some logging with VCDS:

    1. Log block 115 for boost and check that Actual boost is meeting Requested boost throughout the rev range as below.
    [​IMG]

    2. Log block 114 for the N75 Duty Cycle (for N75 read wastegate) and check that after the turbo has spooled the N75 is not working too hard. Before the turbo spool the duty cycle should be at 100% as the wastegate is 100% open. After it spools it should remail at 40-60%. Any higher and it indicates a boost leak because your N75 is having to work to hard to maintain requested boost pressure. Here is what a healthy N75 cycle looks like:
    [​IMG]
    #9
  11. c41lum
    Offline

    c41lum Member

    Joined:
    Feb 11, 2010
    Messages:
    55
    Likes Received:
    0
    [Mar 30, 2010]
    thank you KRL ill get on to that when i return home and let you know! much appreciated
    #10
  12. Phil_T
    Offline

    Phil_T Revo Stage 2+ Audi S3

    Joined:
    Oct 19, 2009
    Messages:
    242
    Likes Received:
    4
    [Mar 30, 2010]
    Ive got a 59 plate too & have posted up pretty much the same thread except mine has revo stage 1, evoms intake & forge dv. Did logs boost is fine so cant be dv so I think ive got used to it or the clutch might be slipping on mine
    #11

Share This Page