Camshaft Seals

Discussion in '308/328' started by Mike Florio, Aug 17, 2019.

  1. Mike Florio

    Mike Florio Formula Junior

    Jun 19, 2003
    NW Rural Nevada
    Full Name:
    Mike Florio
    After an engine-out top end refresh - replace sodium exhaust valves, all gaskets and seals, new hoses, etc.
    Documented here:
    My sons and I finally started the 308GT4 this past weekend.

    Started instantly on the first click of the starter with an eyeball tuneup:

    No leaks anywhere, fuel, coolant, vacuum, except for a small leak at the rear bank exhaust cam seal (where the air pump pulley goes).

    Upon close examination the cause of the leak was immediately apparent: The valve cover gasket was a little too big and distorted the seal. Look at the 10:00 o'clock and 4:00 o'clock positions on this photo - the gasket is green. The distortion is most pronounced at the 10:00 o'clock position.

    The gasket pushed the outside of the seal in, made it oblong, and opened up a gap on the inside where the oil leaked out. The seal popped right off and you can see where the gasket is in the seating surface a couple of mm.

    The seal itself is fine, all I have to do is trim that gasket and tap it back in and it should be OK, but I ordered a couple of new ones anyway. It's a pretty standard 56 x 40 x 7 mm seal. Available here for $3.75 each:

    The point I'm making is that if any of your camshaft seals are leaking check the gasket where the cam cover attaches to the head. Unless that gasket is trimmed carefully it might be the source of your problem.

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    Milkshaker0007, absostone and thorn like this.
  2. thorn

    thorn F1 Rookie

    Aug 7, 2012
    Tallahassee, FL
    I trim the ends as well, to be flush with the outer edge where the caps go.
  3. ferrariowner

    ferrariowner Formula Junior

    Feb 21, 2014
    Mansfield, TX
    Full Name:
    It's a common mistake. A dab of sealant where the seal and gasket meets also helps. Good luck.
    Milkshaker0007 likes this.
  4. yelcab

    yelcab F1 World Champ

    Nov 29, 2001
    San Carlos, CA
    Full Name:
    Mitchell Le
    You trim that gasket so that it fits the seal.... before you install the seal. Bet you won't make that mistake next time.
    27811 and ferrariowner like this.
  5. colinoz

    colinoz Karting
    Silver Subscribed

    Mar 3, 2010
    Raymond Terrace, Aus
    Full Name:
    Col Goldie
    Those seals are also available in Viton, for high temperatures. They are red(ish).

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