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  1. #1
    Petty Officer 3rd Class
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    Default omc cobra 4.3 liter water in cylinders

    Engine has water in all cylinders.

    Could this be a blown head gasket or would you expect the motor has cracked from lack of winterizing?

    Anyone know the steps to go through to find out?
    Remove head gaskets maybe?

    Thanks Mike
    Last edited by marinemike43; July 16th, 2009 at 07:25 PM. Reason: info

  2. #2
    Fleet Admiral
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    Default Re: omc cobra 4.3 liter water in cylinders

    Remove all the spark plugs, clear cylinders of water, remove hose going to the exaust manifold, connect to garden hose ,see if water comes out a spark plug hole, do the same for the other manifold, then cap off those ports or kink the hoses, adapt a garden hose to the water inlet at the therm housing, turn on water,see what runs out,
    more that 1 cylinder cracked block, 2 together ,head gasket (maybe)
    more than 1, cracked block
    out the dip stick, cracked block
    Let us know what you find

  3. #3
    Petty Officer 3rd Class
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    Default Re: omc cobra 4.3 liter water in cylinders

    OK if water does come out of spark plug holes what does this mean?

  4. #4
    Supreme Mariner
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    Default Re: omc cobra 4.3 liter water in cylinders

    Boy, i would not recommend that test to anyone. Why introduce water into the motor?

    The results mean that the manifold has rotted out or a gasket is leaking. Time to pull the manifold and inspect it for leaks from the waterjacket into the exhaust passage.

    Make sure you expell all the water from the motor and change the oil if you have any doubt that it has water in it. Take a compression test. Any two adjacent cylinders with low compression might mean blown head gasket.
    Check the other manifold as well.

  5. #5
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    Default Re: omc cobra 4.3 liter water in cylinders

    Results:

    Filled manafolds,no water came out of them or the plugs.

    Filled intake hose to front water pump and got water only out of the dipstick.
    (Not good) also oil fill on valve cover was full of water.
    And water is leaking from the starbord side head.


    Do you think the bock is cracked or blown gasket or both?


    Any thoughts? (Nothing ever came out of the plugs)

    Thanks Mike
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    Last edited by marinemike43; July 17th, 2009 at 11:11 AM. Reason: info

  6. #6
    Lieutenant Junior Grade danond's Avatar
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    Default Re: omc cobra 4.3 liter water in cylinders

    Sounds like the block is busted.
    1989 Starcraft 171S Select "Cap'n Crunch" / OMC Cobra 4.3 V6 / 432APRMED

    If you're going to keep that OMC Cobra, please for the love of everything good in the world, get an OMC factory service manual. Not a Clymers, Not a SELOC. You can find them on eBay.

    My boat repair website: http://transomfix.dcpolk.com


  7. #7
    Petty Officer 3rd Class
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    Default Re: omc cobra 4.3 liter water in cylinders

    Sounds like a cracked block since you put water through the engine water circ pump and it came out the dipstick.

  8. #8
    Moderator Bondo's Avatar
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    Default Re: omc cobra 4.3 liter water in cylinders

    Do you think the bock is cracked
    Yes...
    Any Grease is Better,..... Than No Grease at All.......

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