308 Head Gasket Leaking Oil?????? | FerrariChat

308 Head Gasket Leaking Oil??????

Discussion in 'Technical Q&A' started by BillyD, Jun 4, 2009.

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  1. BillyD

    BillyD Formula 3
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    Feb 28, 2004
    1,828
    Pacific Northwest
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    Bill
    I've been chasing oil leaks on my 77 308 for some time. I finally added dye to the engine oil to find the last leak that was oiling down the front bank of the engine under the distributor. Believe it or not its not coming from the distributor or associated distributor block seal. It seems to be coming from the head gasket. I searched the threads & find none that describe an oil leak between the head & block. Any one have experience here? Its hard for me to believe, but I can't find anywhere else that it could be coming from. Is there a pressurized passage near the rear of the engine? Anyone have a good picture of this area?
    Thanks
    Bill
     
  2. samsaprunoff

    samsaprunoff F1 Rookie
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    Jun 8, 2004
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    Edmonton, AB Canada
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    Sam Saprunoff
    Good day Bill,

    No direct experience with this issue, however, there could be a number of reasons why this is happening:

    a. Heads require a re-torque
    b. Head warped do to an engine overheat (i.e. boil over), etc
    c. Head to Block mating surfaces were not thoroughly cleaned. Perhaps some residue was on the mating surface(s) and so this is preventing the gasket from sealing
    d. Head cracked (?)

    I would re-torque the heads and see if this helps. If not, then I would do some additional tests (leak-down, etc) to help identify head integrity.... although I would imagine you would see other issues if this was the case (poor performance, oil in coolant, coolant in oil, etc).

    Cheers,

    Sam
     
  3. 2NA

    2NA F1 World Champ
    Consultant Owner Professional Ferrari Technician

    Dec 29, 2006
    18,221
    Twin Cities
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    Tim Keseluk
    There is an oil passage in the area you describe that supplies oil to the camshafts (IIRC through a hollow dowel pin). It is not too unusual to have a leak there. Probably all you can do is try re-torquing the head although I wouldn't expect success from this. The most likely fix would require a new head gasket and possibly resurfacing the head.
     
  4. Mike Florio

    Mike Florio Formula Junior

    Jun 19, 2003
    599
    NW Rural Nevada
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    Mike Florio
    I realize you said it looks like it is coming from the head gasket but it could be from another source. Are your camshafts plugged? There was a tech bulletin on this many years ago which I can dig out for you. Also there is a rubber O ring near the splines on the distributor shaft. It didn't do much to prevent oil from the hollow camshaft getting into that casting that holds the distributor, hence the plug.

    Carefully mark the position of the housing and the rotor and remove the distributor. Then stick a piece of coathanger wire into the axial hole in the camshaft. If it goes in more than about 5" you need to remove and plug your camshafts. I would live with the leak until your next belt change then take care of it. Removing the cams sure makes valve adjusting easy. Search the articles here and there are plenty of postings on the procedure.
     
  5. BillyD

    BillyD Formula 3
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    Feb 28, 2004
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    Bill
    Thanks for the replies, I agree, I think its the head gasket, but if the head has to come off then its valve job time to get rid of the sodium valves, which leads to flowing the heads, & maybe higher compression pistons. I think I'll let it leak for the year in hopes in plugs itself up (yeah, right).
    Bill
     

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