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Pressure Testing Turbo Hoses.

Discussion in 'A3/S3 Forum (8L Chassis)' started by jm-baker, Mar 24, 2007.

  1. jm-baker
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    jm-baker Member

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    [Mar 24, 2007]
    I tryed pressure testing the hoses on my S3 today.

    I made a 80mm plug, put a shrader valve in it, and put it on the inlet hose, where it connects to the MAF.

    I then removed one of the hoses connecting to the inlet hose (the larger of the two) and plugged it off. From what i can see, this hose i removed is the breather hose for the engine, as it connects back to the top of the head ?? The smaller of the two i left attached ( goes too vent side of N75 valve).

    When i apply pressure i can hear what sounds like oil bubbling in the sump, as if air is leaking back into the engine. Tho i can see no other route it could get there other than the hose i plugged off.

    Any ideas ??

    Any help would be much appreciated!!

    I cant seem to find a good write up on how to do a pressure test, and i have no manual to refer too.

    Cheers
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  2. Jamesh
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    Jamesh Member

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    [Mar 24, 2007]
    #2
  3. jm-baker
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    jm-baker Member

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    [Mar 24, 2007]
    Thanx 4 the link, iv not seen that site before.

    Reading it, it seem to be exactly what i did today, so im not sure why i can hear the bubbling inside the engine when i add pressure??
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  4. dummi
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    dummi smoking a6

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    [Mar 25, 2007]
    when you say after the MAF , did you mean after the turbo? the intake does have breather pipes into it.
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  5. jm-baker
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    jm-baker Member

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    [Mar 25, 2007]
    No, after the MAF. I took the hose off the MAF meter and put my test plug with valve in at that point.

    The two hoses i then refer to are the two that tee off that hose, before it goes onto the turbo.

    James
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  6. jm-baker
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    jm-baker Member

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    [Mar 28, 2007]
    Been thinking about this more, could the pressure be going through the turbo bearings and into the oil lines some how? i really want to get this pressure test done.....
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  7. dummi
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    dummi smoking a6

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    [Mar 28, 2007]
    if your bearings seals are gone yea , you'd also be getting oil leaking into your turbo and being blown through the exhaust.
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  8. Jamesh
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    Jamesh Member

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    [Mar 28, 2007]
    Just a thought did you block off the pipe that goes to the throttle body, it could be leaking through TB butterfly or through the idle control valve.
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