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  1. #1

    Default Help identifying this 'knock' on a 1965 CC 283

    Here's a link to a YouTube video - you can clearly hear the knock.


    The knock is intermittent, both in that it doesn't occur every revolution when the engine is running, nor does it occur every time I run the engine, so I'm pretty sure it's not a spun bearing. The sound 'seems' to be coming from the forward left side of the engine.

    I have checked the flywheel - solid - and all the flywheel bolts - tight.
    I have checked that the starter is solidly bolted on and not moving.
    I removed the valve covers and ran the engine. All valves are operating as they should, all with the right amount of travel.
    I've looked inside each cylinder with an inspection cam, no loose objects, none of the spark plugs were damaged.
    I've removed the intake manifold and looked inside each intake port. No loose object, no apparent damage to the valves or sign that anything has been rattling around.
    I removed the inspection plate on the side of the oil pan. No loose objects or metal chips/shavings in the bottom of the oil pan. Both a magnet and a clean rag came out with no 'gritty' stuff.
    I removed the oil filter and cut it open. No metal bits in their either.

    Anyone got any other ideas? Pulling the engine is a last option because it's a hard top boat and I can't get a crane over the engine hatch.


  2. #2

    Default Re: Help identifying this 'knock' on a 1965 CC 283

    Of all the strange things, it turned out to be a loose motor mount.

  3. #3

    Default Re: Help identifying this 'knock' on a 1965 CC 283

    OMG! Really? Glad you got it fixed! Thanks for letting us know
    My Motto Is:
    K.I.S.S.- Keep It Simple Stupid!
    Or, It Might Get Real Expensive!

  4. #4
    Join Date
    May 2016
    Alcoa, TN

    Default Re: Help identifying this 'knock' on a 1965 CC 283

    Mine does the exact same thing. Thanks! I'll check the mount next time I'm on board.

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