1988 Sundancer 268 .. My worst nightmare?

Discussion in 'Classic Sea Rays' started by Jack W. Williamson, Aug 8, 2018.

  1. Jack W. Williamson

    Jack W. Williamson Member

    109
    Nov 3, 2017
    Syracuse, NY
    1988 268DA Sundancer Single 454
    454 7.4 L Mercruiser Alpha one
    So I'm on plane, glance at temp gauge rising, back off, settle into water, i shut the engine off (454 big block) and wait about half hour for temp gauge to get normal. Turn the key, snap the Bendix off. Call towboat. ($340) to pull me 1000 feet. Next day mechanic tells me it's hydrolocked. He removed spark plugs and turns ngine with new starter ($360). He gets water out, I check the oil, it looks perfect. He thinks the best thing to do is replace the engine because he thinks the block is cracked. Is there a way to determine if the block is cracked? I'm looking at$6300.00 for s Jasper rebuild installed. What next? Any comments, suggestions, and condolences welcome! Haha
     
  2. Golfman25

    Golfman25 Active Member

    191
    Sep 12, 2009
    IL
    281
    V8
    He thinks the block is cracked? Or knows the block is cracked? I'd get a second opinion before a dropped $6300 on an "I think."

    I would imagine that you could see the crack and/or something will be leaking from the crack. I don't really know.
     
  3. Bt Doctur

    Bt Doctur Well-Known Member

    Aug 21, 2010
    New Jersey
    Ex SRV 240 Weekender twin
    in between
    Find another mechanic ,
    there are tests you can do to determine what happened.
    It could have happened if you backed off the throttle or just shut the key off and had a backrush of water up the exaust
     
  4. Jack W. Williamson

    Jack W. Williamson Member

    109
    Nov 3, 2017
    Syracuse, NY
    1988 268DA Sundancer Single 454
    454 7.4 L Mercruiser Alpha one
    Yes, that is what happened. Could the lake water rushing in to an engine that is running around 218° bust the block? What is an example of a test to determine if the block is busted? You're right, this is huge money.
     
  5. Bt Doctur

    Bt Doctur Well-Known Member

    Aug 21, 2010
    New Jersey
    Ex SRV 240 Weekender twin
    in between
    Drain the manifolds and risers
    remove the plugs and spin the motor to get out any water. dry the plugs and reinstall them .You list a big block but also a Alpha drive, is this correct.
    Then shift into fwd and remove the drive. Attempt to start the motor and allow it to run 10-20 seconds to dry the cylinders..
    Remove manifolds/elbows and test for leaks.
    Compression test is next.
    If number are all good and even , install manifolds/elbows . insert water hose into water inlet , turn water on . Your looking for water to exit a plug hole. This can be a crack or head gasket. If no water exits , install plugs ,start motor .
    Check for water in oil /discoloration, etc.
    Check your messages too
     
  6. Jack W. Williamson

    Jack W. Williamson Member

    109
    Nov 3, 2017
    Syracuse, NY
    1988 268DA Sundancer Single 454
    454 7.4 L Mercruiser Alpha one
    Thanks for the great thought provoking post to my most recent dilemma, haha. Three one 5415 four six 45.
    Jack
     
  7. Ottawamerc

    Ottawamerc Member

    49
    Mar 23, 2016
    Kemptville
    1987 model on a Karavan tri axle trailer pulled by a 2016 F250 7.2L XLT
    7.4 Mercruiser
    I got lucky with mine Jack, same as yours but with a Bravo outdrive. I sea tested my "new" used 454 and I had temps all over the place. Upon inspection of the thermostat i noticed flakey rust in the bottom of where the thermostat sits in the intake manifold. I picked at the rust and Holy!!!! there was a hole rusted in the manifold right to the rocker gallery!!!! By just plain luck the rust blocked the perforation and didn't fill my engine with water. Possibly something similar with yours?
     
  8. Jack W. Williamson

    Jack W. Williamson Member

    109
    Nov 3, 2017
    Syracuse, NY
    1988 268DA Sundancer Single 454
    454 7.4 L Mercruiser Alpha one
    I put 27 hours on it since May 8. Ran great. I think something blocked the water inlets on the outdrive and all the other bad shit followed once it heated up. I don't think the temp reached, 220°, maybe 218°max
     
  9. Ottawamerc

    Ottawamerc Member

    49
    Mar 23, 2016
    Kemptville
    1987 model on a Karavan tri axle trailer pulled by a 2016 F250 7.2L XLT
    7.4 Mercruiser
    Hey Jack, have you located the cause of the water intrusion yet? hope it's not too bad.
     
  10. Jack W. Williamson

    Jack W. Williamson Member

    109
    Nov 3, 2017
    Syracuse, NY
    1988 268DA Sundancer Single 454
    454 7.4 L Mercruiser Alpha one
    Not yet my friend. I'm pulling the boat tomorrow morning and hauling it from NY to PA. 328 miles. I'll know in a month. I'm also waiting to hear from my insurance guy on my claim. Keep in touch.
    Thanks.
    Jack
     
  11. Handsome Transom

    Handsome Transom Active Member GOLD Sponsor

    256
    Jan 26, 2018
    Penetanguishene Ontario Canada
    1989 SeaRay Sundancer 268 454 Bravo
    454 Mercruiser bravo drive
    So Jack sorry we didn't connect by phone again the other day. I had only wanted to encourage you to ensure all the peripherals get taken care of after you get another opinion on your engines condition and repairs needed.
    I would be sure to remove and inspect every hose in your cooling circuit . Inspect by literally looking right through them for obstructions . Manipulate them bending and looking for any signs of cracking or excessive softness . Personally I would replace them all. Also manipulate the equaliser balls that are fitted with a rod and spring through the t stat housing . Replace the exhaust tubes and butterfly valves at the y pipe. Have you gotten a compression test and leakdown test on the block done . I am really curious on your 2nd mechanics assessment.
     

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