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My Gauge shows -5 vac at idle

Discussion in 'A3/S3 Forum (8L Chassis)' started by Kodak, Mar 31, 2013.

  1. Kodak
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    Kodak Member

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    [Mar 31, 2013]
    My Gauge shows -5 vac at idle it used to show -14 i found a small leak in the gauge hose and replaced it and now it read -5 at idle?
    #1
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  3. jay1601
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    jay1601 Well-Known Member

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    [Mar 31, 2013]
    either a incorrect gauge or vac leak somewhere.

    mine sits at -20
    #2
  4. Kodak
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    Kodak Member

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    [Mar 31, 2013]
    thought as much well best get to it any suggestions where to look first. and how the hell are you getting 34.2mpg lol im lucky if I get 22
    #3
  5. jay1601
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    jay1601 Well-Known Member

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    [Mar 31, 2013]
    not always driving on boost lol.

    average mpg 34.2
    last mpg 29.2
    best mpg 40.2
    #4
  6. Kodak
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    Kodak Member

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    [Apr 1, 2013]
    well I found a leak on the connection to the gauge and fixed that now im reading -15 does this mean I have another leak?
    #5
  7. Lemon S3
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    Lemon S3 Alex

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    [Apr 1, 2013]
    I think mine reads about -15 and I don't have a leak.
    #6
  8. Kodak
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    Kodak Member

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    [Apr 1, 2013]
    holy sh1t I just found another connecting to the brake servo and found an article on about it on tyresmoke aparnetly its only common with APY blocks Audi S3 8L 210 APY Brake Vacuum Hose repair not sure if its ok to link to another forum if not ill remove it Regards
    #7
  9. Westy
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    Westy Double Dark Side! Diesel & 8P

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    [Apr 1, 2013]
    Mine is around -14 and no leaks.
    #8
  10. Tim_Attard
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    Tim_Attard Active Member

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    [Apr 1, 2013]
    mine is about -0.7/-0.8 bar so thats about 10-11 psi should i check for a leak? or would it just be the guage isnt that accurate (got a cheapy)
    #9
  11. Yohan87
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    Yohan87 Member

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    [Apr 1, 2013]
    Mine shows -20 (no leaks) and if I'm driving then let it coast it shows about -22/-23. Newsouth gauge if that makes any difference.
    #10
  12. Kodak
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    Kodak Member

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    [Apr 1, 2013]
    I haven't replaced the brake servo vacuum line yet but im getting -15 and like you say about coasting I was getting -23-25
    #11
  13. s3dave
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    s3dave TFSI Hybrid

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    [Apr 1, 2013]
    If mine doesn't sit at -20 in hg i know i have a leak..
    #12
    phil miller likes this.
  14. Kodak
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    Kodak Member

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    [Apr 2, 2013]
    hi now its not dumping boost why!? its one thing after the next i did notice that it had an aftermarket DV its a Forge Split R any ideas before i get someone to go in to the back of me and write it off "kidding"
    #13
  15. s3gazz
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    s3gazz Active Member

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    [Apr 2, 2013]
    Mine sits at -25
    #14
  16. Yohan87
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    Yohan87 Member

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    [Apr 2, 2013]
    Get rid of the Split-R valve, it's pretty much an expensive boost leak.
    #15
  17. Tim_Attard
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    Tim_Attard Active Member

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    [Apr 2, 2013]
    hi id fit an orginal dv to see if it cures it HOWEVER saying this i have a split r and just measured my vac with torque and getting between 22-26
    #16
  18. Kodak
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    Kodak Member

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    [Apr 3, 2013]
    so go for OE original dump valve? actually I think ill fix the brake servo vacuum line first to see if that sorts the vac problem maybe not enough vac to operarate the dv
    Last edited: Apr 3, 2013
    #17
  19. Kodak
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    Kodak Member

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    [Apr 3, 2013]
    Update ive been to Audi and ordered the parts i wouldnt care but after paying for them and driving a mile up the road and popping in Aldi for some milk and veg it was dumping again.. ??!??
    invoice.jpg
    #18
  20. Kodak
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    [Apr 8, 2013]
    changed the brake vacuum pipe that runs of the inlet mainfold to the brake servo and it still says -14 but on the plus my brakes are better.
    #19
  21. phil miller
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    phil miller Member

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    [Apr 9, 2013]
    Ron's sits at 22 inhg at idle, if i coast/or on over run it goes to around 28inhg, no leaks here :) (there better not be any lol)
    #20
  22. Kodak
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    Kodak Member

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    [Apr 19, 2013]
    right i changed the forge split r dump valve and put a standard one in and now! i get -21 vac at idle :) so problem sorted thanks all
    #21
  23. phil miller
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    phil miller Member

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    [Apr 20, 2013]
    update now mine is at 25inhg, so im sure i dont have a leak now :)
    #22
  24. scotty_24
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    scotty_24 Member

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    [Apr 21, 2013]
    I'm at -7 bar at idle is this ok?
    #23
  25. darren t
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    darren t Member

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    [Apr 22, 2013]
    I have noticed a change in my vacume response ie when you dip clutch how quickly does your idle vacume change mine takes a while too settle if you understand ie it used too go straight up too-0.7 now it struggles any ideas throttle body cleaned??
    no leaks ect.....
    #24
  26. Kodak
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    [Apr 23, 2013]
    hmm ive not had that problem it returns very fast i do however have a problem of over revving when i dip the clutch sometimes anyone seen this its a APY block
    also like to add that is mine is sitting at -24 now since i deleted one of the bends in the vacuum lines so very happy now.
    #25

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