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1985 3870 Stbd engine problems-gctid810256

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  • 1985 3870 Stbd engine problems-gctid810256

    Hello everyone I am new to the site and I'm also a new owner to a 1985 3870 motor yacht. On the first trip of the season we had a exhaust manifold leak on the starboard main engine right at the head. We lost fluid from the bolts but we are able to maintain coolant until we made it back to port. I had a Diesel mechanic look at it today to give me a quote but I am afraid if it is not the manifold and if it is a cracked block instead that we might need to pull the starboard main. Needless to say I am less than satisfied but as of right now I'm thinking worst-case and scenario. Have any of you pulled your starboard main from your 3870 or similar motor yet? I assume it comes out the port access door and not through the deck hatch in the salon, correct? The boat is powered with Chrysler Mitsubishi CM 655 TI engines. It looks like it might be hard enough finding parts, currently doubting this purchase but the boat is beautiful and love the layout she has. Let me know if any of you have any tips or tricks or advice. Thanks and so far the Bayliner is on our club is a great site and I have been doing lots of research I think you are in advance. John
    Great Lakes

    The Wonder Years
    1985 3870 MY

  • #2
    If you give me your email address I can send you a list I have with of sources for parts, and contacts, including complete engines.

    My email is "[email protected]" if you want to contact me.

    1984 3870 with Mitsubishi's
    located in Deep Cove, North Vancouver, B.C.
    Retired Tugboat operator
    Past Commodore Burrard Yacht Club
    Member Deep Cove Yacht Club


    • #3
      Can you get in there with a flashlight for inspection and maybe take some pictures?

      Your manifold is bolted to the engines head. The head is bolted to the block. IF you have coolant leaking from around a manifold stud, I can think of a couple generic items to either look for or try and research:

      -On some brands of engines I've experience with, sometimes a manifold stud/bolt will penetrate the cooling jacket by design. Sealant is used to prevent leaks.

      -Freeze plugs can fail and leak coolant. While not a Chrysler, my Hino 175 has multiple freeze plugs on the exhaust manifold side of the engine, above and below the exhaust studs. This is an easy fix.

      -If the manifold cooler has jacketed exhaust runners, then you might have a leaking manifold to head gasket.

      -if an exhaust runner is cracked and leaking coolant, they can be repaired in certain circumstances.

      That being said, the head can be removed without pulling the engine. I have seen Hino's removed out of the floor hatch by stripping the engine and using 2 frames and come-a-longs on each end and rotating the engine up and into the salon. The engine was then removed with a boom truck reaching into the salon.
      . . .It places the lotion in the Basket. . .and that basket happens to be in a 1987 Bayliner 3870 w/ Hino 175's


      • #4
        I do not believe it necessary to pull the engine to replace the head if thst really is the problem. A call to Earl might help you narrow it down.
        Started boating 1965
        Bayliners owned: 26 Victoria, 28 Bounty, 32, 38, and 47 since 1996


        • #5
          After reviewing it more with another mechanic it looks like it's going to be tearing down the manifold and replacing the gaskets. Now the search for parts begin. Manifold elbow gaskets and manifold gaskets.
          Great Lakes

          The Wonder Years
          1985 3870 MY


          • #6
            I replaced my exhaust manifolds on my 130 MIT's few years back. Keith a Blue Ridge Marine in WA, had parts I needed. Pricey, but the right stuff.
            1994 OCEAN 48' Super Sport w/ 775hp Detroits, Hampton, VA
            1983 HATTERAS 43' DCMY w/ 410hp Detroits, Richmond, VA

            1993 4387 w/ 250 Hinos - Hampton, VA, SOLD
            1996 3388 w/ 150 Cummins - Richmond, VA, SOLD
            1989 Sea Ray 390 w/454 Mercruisers SOLD
            1983 3288 w/ 3.8 Chevy V6 gassers SOLD
            1984 3870 w/ 135 Mits SOLD