Breather Suction??

  1. Super Moderator Joined: Sep 2006 Wakefield Posts: 14427 Golf GT
    #1
    to cut a very long story short my engine is sucking rather than blowing.

    i have recently changed my BMC and put the standard airbox back on and there is a whistling noise. this is because my engine is wanting to suck air in rather than blow air out. when you take the rocker cap off (where you put the oil in) the engine is sucking. thanks to rickyp for spotting it
    its like the throttle body is pulling in way too much air and is resulting in the engine wanting to suck air in. however the car runs fine.

    the only major engine work i have had done recently is my head gasket done. i have spoken to a few people and they cant think of anything that could have caused this to happen as a result of having the head gasket done.

    does anyone know why its doing it?

    any help would be greatly appriciated
  2. Super Moderator Joined: Sep 2006 Wakefield Posts: 14427 Golf GT
    #2
    up dated first post
  3. Saxperience Post Whore Joined: Mar 2007 Reading Posts: 8980 French tin can
    #3
    Have you blocked up the main breather pipe with the induction kit?

    You should have a breather system which takes waste gasses and feeds them back into the induction. Anyway, this breather system will flow air both ways depending on manifold pressure. When the car is idling, you will have high manifold pressure, which in turn, will cause the breather to suck outside air inwards. When you open the throttle, causing low manifold pressure, the breather system will push gasses outwards, normally into the induction system so they can be burned. As these gasses aren't exactly desireable when seeking out and out performance from an engine, people tend to alter the breather flow to a catch tank, so the oil vapour contents of the gasses can be collected and also not hindering performance.
  4. Super Moderator Joined: Sep 2006 Wakefield Posts: 14427 Golf GT
    #4
    ^^ dont think so mate. will have a look though.

    i understand what you are saying but on idle it is sucking un-like my mates vtr which was "puffing" air out. if you take the breather pipe off that goes to the air box and put your finger over the rocker filter end then it makes the whistling noise
  5. Saxperience Post Whore Joined: Mar 2007 Reading Posts: 8980 French tin can
    #5
    What exactly do you mean by "rocker filter end" ?

    Well, as said already, while idling, it should be sucking air in...
  6. Super Moderator Joined: Sep 2006 Wakefield Posts: 14427 Golf GT
    #6
    ^^ i mean the pipe that comes out of the rocker cover and goes to the air box.

    so when the revs are on the the engine should be blowing air out? if yes then how come my mates vtr blows air out when its idling?
  7. Saxperience Post Whore Joined: Mar 2007 Reading Posts: 8980 French tin can
    #7
    I don't know mate, sorry. Doesn't sound like there's an issue with yours though.
  8. Super Moderator Joined: Sep 2006 Wakefield Posts: 14427 Golf GT
    #8
    so when i put the breather pipe back on (the pipe that goes from the rocker cover to the air box) it will still make that whistling noise, do you know why?
  9. Saxperience Forum Bum Joined: Apr 2005 W.Yorks/W.Sussex Posts: 3982 MK1 VTS
    #9
    It's a bit out there but here goes......

    Is it possible that your ECU adapted too the fact that the BMC increased the airflow into the engine? If so, because the standard intake is more restrictive, is it possible that the ECU hasn't reset back too the standard airbox and is therefore sucking like a thai '$10'?

    Then again I'd imagine that would be isolated around the throttle body.

    Bollocks, dunno mate.........
  10. Saxperience Post Whore Joined: Mar 2007 Reading Posts: 8980 French tin can
    #10
    What's whistling exactly mate? Where is it coming from?

    LOL Adam. You'd better give me some suki suki with that! Some love me long time or sumit.
  11. Super Moderator Joined: Sep 2006 Wakefield Posts: 14427 Golf GT
    #11
    thats the thing i dont know whats whistling as i cant find it. it seems to be coming from the the breather pipe on the rocker cover. it has now stopped as i have a breather filter on it instead of the pipe
  12. Established Member Joined: Jul 2007 anglesey Posts: 1055 saxo vtr turbo
    #12
    what bout the pipe to the inlet manifold? u put that back on? probs stupid question, but you never know
  13. Super Moderator Joined: Sep 2006 Wakefield Posts: 14427 Golf GT
    #13
    yes mate thats on or it wouldnt run
  14. Established Member Joined: Jul 2007 anglesey Posts: 1055 saxo vtr turbo
    #14
    yes it would run.
  15. Super Moderator Joined: Sep 2006 Wakefield Posts: 14427 Golf GT
    #15
    ok then, we must be thinking of different parts. when you say inlet manifold what do you mean?
  16. Established Member Joined: Jul 2007 anglesey Posts: 1055 saxo vtr turbo
    #16
    the inlet manifold that has a block on the top of it that has a vacuum nipple for ecu and breather. and has a butterfly on the way in and has a map sensor on it and a throttle angle sensor and many other things. whatn u thinking?
  17. Super Moderator Joined: Sep 2006 Wakefield Posts: 14427 Golf GT
    #17
    is this after the throttle body?

    a pic would be mint mate
  18. Established Member Joined: Jul 2007 anglesey Posts: 1055 saxo vtr turbo
    #18
    if you could post up a pic of ur engine bay, i will edit it with red circles and label the stuff
  19. Super Moderator Joined: Sep 2006 Wakefield Posts: 14427 Golf GT
    #19
    not got one with the stanadr filter on.

    when the rocker pipe is connected to the airbox then the engine is sucking from the rocker cover where you put the oil in.

    now it just the breather on it blows air out like puffpuffpuffpuffpuffpuff