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Oil Fill Cap Question

Discussion in '80-Series Tech' started by turbocruiser, Feb 21, 2004.

  1. turbocruiser

    turbocruiser SILVER Star

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    Hi folks, I searched this subject but am still wondering whether the oil fill cap is supposed to tightly seal the valve cover area or if it is primarily supposed to prevent oil from flinging out of the cover? The reason I ask, I am seeing a slight residue of motor oil around the oil fill cap. This oil residue appeared right after my last oil change and I think what it is is simply some extra oil that was covering the threads on the valve cover's oil fill cap opening. After the last oil change, I hand tightened the cap and I wiped down the entire area with a shop rag like I always do but I think that extra oil in the threads between the cap and the cover worked its way past the threads of the cap. So I was wondering if this indicates that the cap should be replaced or if it just indicates I should wipe excess oil off the threads prior to putting on the cap! :doh: Also, how normal is a slightly dusty oil residue around the PCV valve and the other hose coming off of the valve cover? Thanks as always.
     
  2. landtoy80

    landtoy80

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    I have a new cap and I have to tighten the cap good to keep the oil in.
    My vent hose on the valve cover seeps a bit too. I think I need a new hose.
    You need a new PCV grommet and get a new PCV too. Don't let the grommet brake apart and fall into the motor or you will have to pull the valve cover.
     
  3. Junk

    Junk

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    fwiw, if the grommet falls in, use an air powered syphon blow gun to get the junk out. works great. yes, I did this.
     
  4. turbocruiser

    turbocruiser SILVER Star

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    Yea, I have replaced both the PCV and the PCV grommet within the last thousand miles so both those are fine. I think what really went on here is that I had lots of excess oil on the threads of the oil cap and on the threads of the valve cover where the oil cap goes. The pressure inside the cover pushed that oil out past the oil cap and then driving down the highway pushed the oil around on the valve cover. In general, I was wondering if the oil cap should really seal really tightly or if some residue of oil around the cap is common. Thanks for the replies folks!
     
  5. cruiserdan

    cruiserdan SupportingVendor Emeritus Moderator

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    You will have a bit of oil that can migrate past thr PCV valve and the oil cap. If you live in a dusty area it will be more evident.

    It is possible to replace just the gasket on the filler cap. ;)

    It is important to look after the PCV valve more often in a forced induction engine. It is a one-way device but some leak-down is possible, even with a new one.
     
  6. landtoy80

    landtoy80

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    I testes my PCV by running the rotor, removing the oil fill cap and put a piece of paper over the oil fill hole and see if it sucks. If it does then the PCV is working.
    I do have some broken PVC in the garage:)
     
  7. IdahoDoug

    IdahoDoug

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    Hmm, "testes" "hole" and "sucks" all in the same sentence. Kurt, that sounds like it would hurt!

    DougM
     
  8. Photoman

    Photoman SILVER Star

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    Here is a little "tool" I made that helps with the PVC grommet removal. You can tie a bow type knot with string around the rubber flaps, put it through the grommet, and pull the ripcord/string. Your chute will open under the grommet to catch pieces or can be used to put upward pressure on the grommet as you remove it. :D 8-32 all thread.

    Bill
     
  9. e9999

    e9999 You want to do what...? Moderator

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    geez... I'm impressed....
    (and you have entirely too much time on your hands... :D) )
    E