Help locating vacuum leak

Discussion in 'General Motoring' started by Michael Chiu, Oct 16, 2003.

  1. Michael Chiu

    Michael Chiu Guest

    OK, a while ago I posted about my Check Engine light coming on and how the
    OBD device codes said that I was running rich.

    Now that I have just lost my job, I have time to try to find the leak on
    my own, which will save me some needed money.

    Someone suggested checking an elbow on a hose somewhere, but I don't know
    how to locate that hose. I'm somewhat mechanically inclined, so I hope I
    can do the replacement if I'm pointed in the right direction. Maybe I
    should take a picture of the engine area and someone can describe it based
    on the picture.

    Thanks.
    Mike
     
    Michael Chiu, Oct 16, 2003
    #1
  2. Michael Chiu

    fountainpen Guest

    What car and model????????????engine,aspiration?????????
     
    fountainpen, Oct 16, 2003
    #2
  3. Michael Chiu

    Mike F Guest

    fountainpen sure has a great question!

    If you're running rich, you don't have the common vacuum leak. The
    common leak on 850s and 70s is in the elbow at the end of the intake
    manifold behind the power steering pump, but not all of them have this.
     
    Mike F, Oct 16, 2003
    #3
  4. Michael Chiu

    Michael Chiu Guest

    Oh man, I did forget to mention my car. It's a 1998 S70 T5.

    I'm not sure this makes any difference, but for some reason, my car sounds
    a bit deeper than it did before the problems arose. It's sort of like the
    sound my 240 was making when the end of the muffler rusted and broke off.
     
    Michael Chiu, Oct 16, 2003
    #4
  5. Michael Chiu

    Mike F Guest

    Aha, there's a clue. An exhaust leak can allow air to be sucked into
    the exhaust as well as allowing exhaust out. If this happens upstream
    of the oxygen sensor(s), then the ECU can be fooled into thinking that
    the engine is running leaner than it really is (too much oxygen in
    exhaust = lean mixture). Of course there's no way it can compensate to
    get rid of this oxygen. Check for leaks from the exhaust manifold down
    to where the oxygen sensors are mounted.
     
    Mike F, Oct 17, 2003
    #5
  6. Michael Chiu

    Michael Chiu Guest

    I think you were on the right track in helping diagnose my problems. I
    took the car to my mechanic today. He did confirm that I had a vacuum leak
    due to a big hole in a hose. He quoted me $75 to fix it (parts & labor). I
    asked him if it was a difficult fix, and he said it wasn't really, but
    since there's not much room to maneuver, he'd have to take out a pump. In
    a post preceding this, you had mentioned the "elbow at the end of the
    intake manifold behind the power steering pump".

    Should I just pay the $75 and be done with it, or should I attempt to try
    the fix myself? Can this be done w/o taking out the pump, or would that
    only be possible if I had tiny hands?

    Thanks,
    Mike
     
    Michael Chiu, Nov 5, 2003
    #6
  7. Michael Chiu

    Mike F Guest

    I think it's possible, but I've never actually needed to do it. I think
    for $75 you should let your mechanic change it, it'll make him happier,
    and he'll be more willing to give you a fair shake the next time...
    Think of it as an investment in this mechanic, he sounds like an honest
    guy.
     
    Mike F, Nov 5, 2003
    #7
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