Welcome to the Hatteras Owners Forum & Gallery. Sign Up or Login

Enter partial or full part description to search the Hatteras/Cabo parts catalog (for example: breaker or gauge)
+ Reply to Thread
Page 1 of 5 1 2 3 ... LastLast
Results 1 to 10 of 49
  1. #1

    Smile "black" coolant anti-freeze

    Hi to all.
    I 've got a 37 c 1981 with 2 DD325hp that sound very well except for a new problem of over heating temperature ( left 190 and right 195/198 ).
    I don't think it could be a problem with headexchanger obstruction as I clean them perfectly last year.
    Now the surprise is that the coolant blue became grey/black.
    I put a little bit of liquid into a Coke bottle and after 5 hour the surprise: 1/4 black mud and 3/4 return to be perfect blue coolant.....
    I desume that all coolant way into the motor are obstructed of mud.
    What do you think about ?? Help me !!!!!!!!!!!!!!!
    an italian hatteras in love.

  2. #2

    Post Re: "black" coolant anti-freeze

    please suggest me how clean mud from coolant system and how avoid to accumalate mud in the future.
    ciao
    roby

  3. #3

    Re: "black" coolant anti-freeze

    Are you saying that the "mud" is in the raw water portion of the cooling system (the part that picks up seawater and circulates it through the heat exchanger and then back out through the exhaust) or in the circulating portion of the cooling system (the part that contains coolant/antifreeze)?

    If the raw water system picks up mud or sand, it cannot get into the coolant portion of the system unless there is a serious problem with a broken or cracked heat exchanger.
    Mike P
    San Miguel de Allende, Mexico; Kent Island MD; San Antonio TX
    1980 53MY "Brigadoon"

  4. Re: "black" coolant anti-freeze

    Very difficult to diagnose problems via vague descriptions like this...I'm not even going to try....
    mud color coolant...
    was the circulating coolant changed last year??...and was clear blue at that time...is this DD approved heavy duty diesel antifreeze....or is it coolant??
    Did you pour off the blue clear antifreeze and inspect "mud" what does "mud" mean?? thick oozy muck..... or are you describing a black color to otherwise blue normally viscous coolant?? Is the coolant circulating??

    overheating....two engines overheating this year when they operated ok last year?? Was this after winter shutdown and winterizing? Did you check raw water impellers?? has the boat been hauled....could outside growth be obstructing engine intakes? Coolant at normal full level in each engine? Do you have jelly fish there which might clog intakes? Did a yard paint over your pinhole engine intake strainers??

    General question: what other work was done on the engines prior to this problem....
    Last edited by REBrueckner; 04-15-2009 at 02:28 PM.
    Rob Brueckner
    former 1972 48ft YF, 'Lazy Days'
    Boating isn't a matter of life and death: it's more important than that.

  5. Re: "black" coolant anti-freeze

    Is it possible that the "MUD" is actually oil that separated out when left to stand?

    Craig

  6. Re: "black" coolant anti-freeze

    Oil in your fresh water system will accumulate on top of the coolant in your expansion tank....stick a finger down through the pressure cap opening and if it comes up black, yea it's oil....but why would that happen in both engines simultaneously?? that's one reason why I asked what work has been done recently on the engines....
    Rob Brueckner
    former 1972 48ft YF, 'Lazy Days'
    Boating isn't a matter of life and death: it's more important than that.

  7. #7

    Re: "black" coolant anti-freeze

    no extra job have been done on motors.
    The sludge is not oil and I saw it because the plastic hose connect at pressure cap of expansion tank arrived into a plastic bottle that I have placed to keep clean the engin motor roof

  8. #8

    Re: "black" coolant anti-freeze

    last year I have only cleaned head exchange with correct product ( DD authorized mechanic) but I have not change the coolant antifreeze

    the sludge is only into the circulating portion of the cooling system ( the part that contains coolant / antifreezre )

  9. #9

    Re: "black" coolant anti-freeze

    impeller have been correctly change one week ago and work correctly,
    intake have been cleaned with my first swimming
    strainer are cleaned

    when I ship at 2100 rpm
    both headxchange are cold
    probably there are no circulation of coolant

    My doubt was if sludge may closed the coolant sistem causing overheating temperature

  10. #10

    Re: "black" coolant anti-freeze

    Quote Originally Posted by REBrueckner View Post
    Oil in your fresh water system will accumulate on top of the coolant in your expansion tank....stick a finger down through the pressure cap opening and if it comes up black, yea it's oil....but why would that happen in both engines simultaneously?? that's one reason why I asked what work has been done recently on the engines....

    no oil in the expansion tank
    only sludge black. I left a bottle of coke full of coolant and after 5 hours 1/4 of sludge on the bottom and 3/4 of cleaned coolant on the top

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts