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  1. #1
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    woz's Avatar
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    PCV details on 940 lpt

    Hi all i hope someone can help. We cleaned out the PCV on the car yesterday, all hoses plus the separator tank. I am confused as there is a connector where the main vent hose goes into the air intake pipe just after the turbo, which has an electrical connector, but does not seem to have anything inside, not that i can see anyway. Should it be a valve or is it a sensor?

    Likewise the small pipe running into the intake manifold ...should it have any valve or is it just a free passge for fumes regardless of manifold pressure? To me it seems there is absolutely nothing to sprevent boosted intake air pressurising the crankcase, and nothing to stop crankcase air being drawn into the inlet, after the throttle body and bypassing the IAC.

    The haynes manual is usless in this regard. Has anyone got a schematic diagram of the pipe run and/or any insights? In particular should there be any kind of check valves?

    As an aside, having cleaned it all out, the oil fumes from the filler cap have reduced, but my son is reporting reduced levels of boost. Wondering if the cleaning has maybe dislodged some one way valve or other maybe?

  2. #2
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    Dangerous Dave's Avatar
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    It's probably like the PTC valve on the 850/x70 turbos (think it's on the turbo inlet piping rather than outlet) http://www.vpcuk.org/forums/showthre...ve-actaully-do

    The pressure from the small hose will probably route back through to the ptc valve an into the turbo rather than going back through the oil separator

    The turbo engine crankcase ventilation is routed differently to the NA engine.

    940 Turbo ventilation diagram (not showing the ptc valve)
    Last edited by Dangerous Dave; Sunday 31st December 2017 at 21:41.
    1996 Olive Green 850 AWD - Forged rods, VXR injectors, 19T, Ostrich 2.0, cold air con. Follow the project here
    1996 Nautic Blue 850 AWD - The daily, resisting the urge to modify

  3. #3
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    woz's Avatar
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    Thanks dave, it makes sense now. I realised after posting that it does of course feed in upstream of the turbo, so it sucks! Lol. That valve being a heater element in disguise explains why it looks like it does. Got it all working, and found the lack of boost was due to the split pin in the wastegate linksge having rusted away and the rod disconnected itself. We must have nudged while cleaning around the turbo. Piggy little job to get the remnants out, so we bodged it with a loop of wire for now pending turbo removal and new actuator. Happy New Year and thanks for the assist.

  4. #4
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    Dangerous Dave's Avatar
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    Ah back to boostly goodness then

    No worries bud, have a fab day!
    1996 Olive Green 850 AWD - Forged rods, VXR injectors, 19T, Ostrich 2.0, cold air con. Follow the project here
    1996 Nautic Blue 850 AWD - The daily, resisting the urge to modify


 

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