Welcome Guest - Sign Up today
Welcome Guest - Sign Up today

Announcement

Collapse
No announcement yet.

2004 4.3 starboard issue after issue possibly blown head gasket???

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • 2004 4.3 starboard issue after issue possibly blown head gasket???

    Hi all. I am planning on tearing into my engine compartment of my 2004 Chaparral Signature 270 with twin Merc 4.3 mpi with Beavo 3s. Impeller went out on Starboard engine about a month ago but the temp alarm shut it down before it got too hot. I pulled the boat out of its slip to take it for service and had new impellers, and both engines fully serviced. I put it back in the water and idled our past the no wake and once it got it up on plane it started feeling a little sluggish but no alarms. I backed it off an tried to take off again to no better outcome. Popped engine hatch and the belt was shredded about 3/4 through and slapping around on everything. I called the boat yard that serviced it and they came down and put a new one on and blamed it on the belts age, (bull crap). Too much coencidence being it was just removed and put back on a few hours ago. I took it back out the next day and ran it about 20 miles or so and on the way home I got another lag in power followed by a huge steam cloud coming from hatch. It blew a hose coming from the water pump up to the top of engine. Again I call the boat yard and they blame the hose damage on the belt beating it up when it shredded. We replaced that hose and the next trip out it blew the elbow off the exhaust boot. Replaced that and now it trying to build pressure and blow other hoses. Friend thinks it’s head gasket or heads. I build houses and have no mechanical knowledge but am going to start pulling parts in the slip this weekend. And help or diagnosis suggestions would be much appreciated. I’m hoping for simple but prepared for terrible!

  • #2
    What is one of the motor serial numbers?
    Are you open or closed cool?

    With this all happening with the same motor I would suggest doing a compression test, starting to sound like a head gasket
    94 Formula 27PC Custom 509MPI MEFI3 , B3 XR
    95 Rinker 232 w/ 7.4L Carb 0F425011 B1 0F486471
    07 Seadoo GTX
    Merc Adults Only VP Adults Only
    G-Dad always said "First Liar doesn't stand a chance"

    Comment


    • #3
      I am not sure if the serial numbers. Boat is 90 minutes away. Closed cooling I’m assuming though.

      Comment


      • #4
        If the head gasket blew it will force gases into the cooling system and pressure will blow hoses. We need the serial number so we know how your motor is configured. Hope to get it later, but do suggest a compression test, and my guess is there was an over heat bad enough to blow a head gasket
        94 Formula 27PC Custom 509MPI MEFI3 , B3 XR
        95 Rinker 232 w/ 7.4L Carb 0F425011 B1 0F486471
        07 Seadoo GTX
        Merc Adults Only VP Adults Only
        G-Dad always said "First Liar doesn't stand a chance"

        Comment


        • #5
          Serial number OM665263 on starboard engine.

          Comment


          • #6
            Yah, closed cooling. Head gasket definitely cause all sorts of afore mentioned issues with your pressurized system. Your mechanic sucks.
            17 Foot '90 Bluewater
            Alpha 1 3.0 Merc - repowered in 2016
            now - 4.3L Vortec - Alpha 1 GenII
            Honda BF100L kicker
            Engine custom - Transom 0D65328 - Drive 0D648864
            If you ain't fishin, then yer working too much.

            Comment


            • #7
              Is the shredded belt coincidental damage? coz I can't think of how a blown head gasket could cause the belt to reap so badly. Unless of course mechanic did not align it properly
              1998 Ebbtide 210 Campione, Mercruiser 5.0 V8, 1993 Larsen Sei 200 BR, Mercruiser 5.0 V8 1990 Bayliner 2050, Mercruiser 3.0LX 1984 Mercedes, OMC 3.8 V.6

              Comment


              • #8
                Actually I am thinking that the smoked belt was due to them not reinstalling it correctly after impeller water pump service work. And that situation is potentially what caused the blown gasket

                Comment


                • #9
                  Sign up today
                  Thanks for the serial number

                  Not backing either outcome, but the timeline is
                  motor overheated at first time and PCM shut motor down
                  Impeller changed
                  motor is sluggish belt shredding
                  replaced belt motor running fine until 20 miles later when hose burst
                  replaced hose
                  Exhaust boot comes off so the motor has gotten so hot that it melted some
                  Pressure is so great that other hoses may bust/blow off

                  Do a compression test to verify, but I see the heads are coming off at a minimum

                  Pull all spark plugs and label each wire. Flip the kill switch (man overboard) to keep motor from starting
                  Move throttle to WOT and one by one install compression gauge and crank motor over at least 4 turns for each test, and record pressure. Your looking for cylinders under 140 psi
                  94 Formula 27PC Custom 509MPI MEFI3 , B3 XR
                  95 Rinker 232 w/ 7.4L Carb 0F425011 B1 0F486471
                  07 Seadoo GTX
                  Merc Adults Only VP Adults Only
                  G-Dad always said "First Liar doesn't stand a chance"

                  Comment

                  Working...
                  X