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noise from engine rm 5.7 litre mercruiser (rattle noise like bbq vibrating )-gctid419042

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    noise from engine rm 5.7 litre mercruiser (rattle noise like bbq vibrating )-gctid419042

    It is a noise that starts at 2500 rpm and i do not go over 3200rpm with the noise increasing with rpm increase. I thought something could be lose but havent found anything yet. Any advice would be good as this is my first I/O engine. I now prefer OB engines atleast you can work on it.

    Pretty tough to diagnose via the limitted info.

    Can you take a video of this and perhaps capture the sound?

    I now prefer OB engines atleast you can work on it.
    I know what you mean.

    There are only three shops in the United States that work on these Merc I/O's.


    Actually, once you learn about I/O's and I/O engines, they are relatively simple to work on.

    Rick E. Gresham, Oregon
    2850 Bounty Sedan Flybridge model
    Twin 280 HP 5.7's w/ Closed Cooling
    Volvo Penta DuoProp Drives
    Kohler 4 CZ Gen Set


      i will have to say you can easily work on an i/o as compared to an outboard not only that if you ever need to replace motor if it is 150 hp and up you will be real glad cost wise you got an i/o. they have problems like anything else but are not nearly electrical as an outboard motorout and repairs generaly if you cant do it yourself outboards can cost quiet a bit for the specialty mechanics .not to mention motor in boat so if break down i/o are easier to get to to get going with minimal tools. good luck hope it is minor but sounds like may be something serious cause it increses with rpm hard to tell without hearing it knocking not good you can use a long screwdriver or socket extension hold to motor and your ear try to pin piont were it is comming from up high down low? also check plugs see what they look like they can tell you were to start looking also change your oil into clean container and inspect oil for metalic looking oil hope it is clean if not rod bearings going make sure oil press never goes lower than 20 to 30 psi when hot .good luck! 2850 bounty is realy good i would take his advise he helped me and was right both times.


        Could also be the exaust flapper
        Boatless at this time

        A veteran is someone who, at one point in their life, wrote a blank check made payable to "The United States of America," for an amount of "up to and including their life."


          Alaskanmutt wrote:
          Could also be the exaust flapper
          That's what I was thinking when the rubber wears off the edges on the old style flappers your can hear a noise like an exhaust cover on a tractor trailers vertical pipes bouncing up and down.

          Watching crow being slowly eaten in the PNW.
          The village idiot strikes again.