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Issue boost leak testing AMK

Discussion in 'A3/S3 Forum (8L Chassis)' started by SiGainey, Jun 3, 2011.

  1. SiGainey
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    SiGainey Member

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    [Jun 3, 2011]
    Wondered if anyone had any advice for me here - I connected a boost leak tester to the MAF, undid the oil filler cap, clamped the PCV hose and filled her up with 1 bar of air... Now she wouldn't keep 1 bar in her but I couldn't hear a leak anywhere... Except, there was a bunch of air rushing around the MAF area but soapy water showed no leaks... Any ideas? It's leaking somewhere, else it would hold a bar...
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  3. JamJay
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    JamJay Member

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    [Jun 3, 2011]
    Can you hear a bubbling sound at all? You might be pushing air through a turbo seal which would cause that kind of noise & lose pressure, then on first start up the exhaust would smoke.
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  4. SiGainey
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    SiGainey Member

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    [Jun 4, 2011]
    Yeah, the oil#s bubbling in the sump for sure, from jut a few PSI
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  5. <tuffty/>
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    <tuffty/> Badger 5 Edition Staff Member Moderator

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    [Jun 4, 2011]
    can't easily do a pressure test the way you are doing it... too many places for the air to escape... gap in the throttle, valves open etc and various vac pipes all mean something will leak somewhere... smoke test is the best you can ask for doing it this way... I normally pull the hose from the charge pipe and throttle body and test there as all the others can be done visually... as long as you know the turbo to charge pipe hose is tight and the vac pipes under the inlet mani are sound (including the V pipe on the end) then you are testing the integrity of the hoses you can't get too or see...

    Boost leaks on the charge system are typically from crappy jubilee clips going loose... especially on the connections to the SMIC's... the OEM clips go loose over time, oil blows past and breaks the seal and bingo... the OEM clips are **** too so one idea is to change them for JCS Hi-Grip or Hi-Torque clips... more expensive but you can get them real tight without getting the click of death... if you do get the click of death then bin the clip... its of no use once that happens..

    <tuffty/>
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  6. SiGainey
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    SiGainey Member

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    [Jun 4, 2011]
    Cheers Tufty. Have replaced all the SMIC clips with JCS ones a few month back. Just trying to track down that elusive leak which I can hear but can't find...
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  7. SiGainey
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    SiGainey Member

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    [Jun 21, 2011]
    Following on from this, I got a 63mm hose connector and plumbed it in at the throttle body, put 1 bar in and no leaks... Find that hard to believe IMO. Anyone see a flaw in what I'm doing?

    http://www.youtube.com/watch?v=l_3I_jiyYa0
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  8. SiGainey
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    SiGainey Member

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    [Jun 22, 2011]
    bump?
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  9. s3schofield
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    s3schofield Member

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    [Oct 29, 2011]
    plumb in at the tip maf end block off pcv hocky puck thing in the tip with a bung put pressure in and listen for leaks and use soapy water in a sprayer works wonders on the whole system
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  10. sportstractor
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    sportstractor Chugger

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    [Oct 30, 2011]
    That is a pretty tiny leak dude, if it's not leaking when you cap the pipe off before then it has to be a breather under the manifold?

    I tried testing mine a few times that way, gave up in the end and paid a garage £40 to smoke test it.
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