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boost leak check surrey & inlet mani vac line after n249 bypass

Discussion in 'A3/S3 Forum (8L Chassis)' started by Squirrelofdoom, Jul 26, 2012.

  1. Squirrelofdoom
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    Squirrelofdoom Member

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    [Jul 26, 2012]
    Hi guys,

    So, had some issues doing ym N249 bypass tonight. Not really with the bypass itself, but noticed that my FPR vac line was completely disconnected from the inlet manifold, no idea how long it's been like that. See here: http://www.audi-sport.net/vb/a3-s3-...doing-n249-help-please-i-want-drive-home.html

    So, managed to change the FPR line as I was doing that kind of thing anyway - changed it and the SAI lines to silicone hose. During the N249 bypass, changed all hoses apart from the existing inlet manifold vac line to silicone. Started the car and it was fine, no warning lights or anything. However, I think I can hear a leak from the area highlighted below:

    [​IMG]

    Maybe paranoia - but think I could hear it slightly when driving home. Car still feels ok, but could swear I can hear a leak from there. Can't feel anything though. So, as the red circle shows - I think it's coming from the area on the inlet manifold which has the 2 nipples - one connected to the existing vac line (which I did not replace for new silicone) and the other to the FPR line I just changed. All hoses I changed are secured with small cable ties and are a tight fit anyway. So I'm thinking it can't be the FPR line making that noise - especially as I think that line has been completely off for a while anyway and I didn't notice it before.

    The only thing I can't properly get access to and see is the nipple which connects to the existing inlet manifold vac line. Does anyone have a picture of where that connects? Feeling underneath the manifold, i'm finding it hard to tell if it is still tight or split etc.

    On the same sort of topic, I might want to get a boost leak check done - anyone know anywhere in Surrey which does it well at an affordable rate?

    Thanks guys! Appreciate the help

    Aran
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  3. jezzy
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    jezzy Member

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    [Jul 27, 2012]
    the pipe from the end of the inlet mani where you circled is also a vacuum and the pipe perishes inside change it, its ten mill diameter.
    heres a pic of the under side second post down, kindly donated by westy.
    my local garage said a tenner for a smoke test, but im in kent
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  4. jezzy
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  5. Squirrelofdoom
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    Squirrelofdoom Member

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    [Jul 27, 2012]
    Hi mate,

    I think it's coming from one of the small nipples on the right hand side of Westy's photo - the one which now goes to my T-piece from my N249 delete (originally it went to the N249). Bloody difficult to get to / see because it's the one towards the front of the vehicle and I can't actually get any eyes on it to see it to check / repair the connection :S
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  6. VAB
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    VAB Member

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    [Jul 27, 2012]
    I have a similar issues with min - running, idle good but sounds like small leak in the area you have circled - will let you know how I go after doing more investigation on the w/end.
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  7. Squirrelofdoom
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    Squirrelofdoom Member

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    [Jul 27, 2012]
    cool, thanks VAB - i'll update too if I find anything. Don't really wanna take the inlet mani off if I don't have to - but I could clean my TB if I do...hmmm decisions decisions
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  8. jezzy
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    jezzy Member

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    [Jul 27, 2012]
    that nipple underneath is a fecking pain to get to and tie.
    As explained in the above linky you could do the pcv or evap delete and use one of those nipples for a better connection.
    on the same subject, i had hesitation under wot and found the loom that connects to the coil pack had multiple cracks and holes.
    So i stripped back the loom (not that hard) and fixed all the cracks and holes and all is good now.
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  9. VAB
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    [Jul 29, 2012]
    Checked all around the hoses off the small nipples and the nipple at the end of the manifold and no leak, even though it sounds like there is one there. Found small leak in hoses under the manifold. looks like time to fit a catch can and simplify the PCV plumbing as most have done for me.
    #8
  10. Maverick1
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    Maverick1 Member

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    [Jul 29, 2012]
    Mate, I literally just fixed the same problem when doing my N249 bypass on my S3...Here is what you are dealing with, and and the way I accessed it was to unclamp the the rubber u-shaped hose that is attached to the left end of the manifold (in pic) and then move the whole lot away, I also removed the plate that covers the dipstick area (and broke the dipstick holder while I was at it too) for more access. I just replaced both hoses (DV & FPR) with 4mm silicone and zip ties...

    I found it easiest to put the zip tie on the hose first, tighten it so it "grips" but only just enough to stop it moving, and then just feel around until you find the nipple and push it on - then tighten it by feeling around under there. Have fun!


    [​IMG]
    Last edited: Jul 29, 2012
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  11. VAB
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    [Jul 29, 2012]
    Thanks - Found a good light source also helps a lot
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  12. Maverick1
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    [Jul 29, 2012]
    Actually just re-read your post. I guess you didn't need all that info, but there's a pic showing whats under there anyway. I'd def change the other line to silicon though. If the other was rooted any others can't be too far off either. (",)
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  13. Squirrelofdoom
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    [Jul 29, 2012]
    Hi guys,

    Just finished working on the car today and managed to get to that last nipple and replace the inlet mani vac line, woo! Also found out that when I replaced the FPR line I had cable tied arond BOTH nipples with my cable tie - so I guess that's where I still had a leak. Popped off the inlet mani line (the nipple closest to the front of the car - which I think is easier to get to, but anyway...) and replaced it with silicone and replaced both cable ties. Also replaced N75 line with new silicone while I was at it :)
    #12
  14. VAB
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    [Jul 30, 2012]
    Next job will definitely to replace any old hose that are left
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