Click for Yacht Lettering Click for Westport Click for CL Yachts Click for Llebroc Click for YFYS

Overheating Issue

Discussion in 'Ocean Yacht' started by Boomer, Jun 2, 2018.

You need to be registered and signed in to view this content.
  1. Boomer

    Boomer Senior Member

    Joined:
    Oct 14, 2017
    Messages:
    671
    Location:
    Seminole
    Only 1 zinc? Why 2 holes then? Just curious
  2. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    10,829
    Location:
    Satsuma, FL
    Less zinc & zinc waste (zinc flakes, mud, pieces) to block the small HE tubes at the coolers inlet.

    Should be no problems on less zinc.
    No problems at all if thru hull and cock are bonded.
    Last edited: Aug 9, 2019
  3. Boomer

    Boomer Senior Member

    Joined:
    Oct 14, 2017
    Messages:
    671
    Location:
    Seminole
    Ok...I will remove one from the inlet side
  4. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    10,829
    Location:
    Satsuma, FL
    And look thru it well..
  5. Boomer

    Boomer Senior Member

    Joined:
    Oct 14, 2017
    Messages:
    671
    Location:
    Seminole
    Ok...I will also remove the hose view the 1st cooler screen to make sure no issues...there is good water flow out the tail pipe
  6. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    10,829
    Location:
    Satsuma, FL
    I'm sure it looks good, but you can not tell by eye if 50 GPM or 150 GPM is flowing.
  7. Boomer

    Boomer Senior Member

    Joined:
    Oct 14, 2017
    Messages:
    671
    Location:
    Seminole
    Removed hose and locked at first screen..couple barnacle pieces and some salt residue..cleaned out with coat hanger...took her out saturday..same problem...getting raw water side acid washed today
  8. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,143
    Location:
    Fort Lauderdale
    Follow the raw water from the pump to various components. I had one Detroit where the first stop was the fuel cooler and it was full of broken off zincs. On another Detroit, the raw water pump had a 2" spacer on the intake side and one of it's surfaces was warped and sometimes it allowed the pump to suck air and the motor to overheat and other times it was fine.
  9. Boomer

    Boomer Senior Member

    Joined:
    Oct 14, 2017
    Messages:
    671
    Location:
    Seminole
    Will check if the backflush and acid wash doesn't work
  10. Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,143
    Location:
    Fort Lauderdale
    I also had another one where the raw water side was relatively clean and the coolant side of the heat exchanger was completely clogged with sediment.
  11. Boomer

    Boomer Senior Member

    Joined:
    Oct 14, 2017
    Messages:
    671
    Location:
    Seminole
    Thermostat was good...replaced it anyways...heat exchanger to be pulled and boiled down
  12. Capt Fred

    Capt Fred Senior Member

    Joined:
    Jun 22, 2009
    Messages:
    319
    Location:
    Long Beach CA
    Make sure the screen/strainer on the outside of the hull is clean. My diver forgot to clean mine and it caused me to overheat.
  13. Boomer

    Boomer Senior Member

    Joined:
    Oct 14, 2017
    Messages:
    671
    Location:
    Seminole
    Bottom cleaner scheduled for next week
  14. rtrafford

    rtrafford Senior Member

    Joined:
    Jul 13, 2019
    Messages:
    1,283
    Location:
    Vero Beach
    Wouldn't be shocked to find pieces of zinc, impeller, etc in the heat exchanger point of entry that's helping to disrupt water flow. Good to put a temp gun on both input and discharge of the heat exchanger to discover temp delta. Compare against opposite engine.
  15. MaroonKnighty

    MaroonKnighty New Member

    Joined:
    Sep 1, 2016
    Messages:
    1
    Location:
    Lake Michigan
    Hi, I'm new to this site. I have a 1988 48ss that I bought a couple years ago. My heat exchanger failed on my starboard engine shortly after I bought it. It all happened pretty fast, didn't realize it until engine started chugging, I looked back and tons of black smoke coming out from exhaust and engine room, I thought we were on fire. Not a good thing. I ended up repowering her with brand new Cummins QSC 8.3-600's. She's really fast now and pretty much mechanically a brand new boat, but it was a lot more expensive than one heat exchanger. Get that sucker looked at quick.
  16. Boomer

    Boomer Senior Member

    Joined:
    Oct 14, 2017
    Messages:
    671
    Location:
    Seminole
    Well, between the backflush (nothing came out) and filling the system with barnacle buster for a few hours, it works great again...ran at speed for hours and she purred the whole time...maybe 5 degree creep under speed but stopped around 190 or so
  17. Capt Fred

    Capt Fred Senior Member

    Joined:
    Jun 22, 2009
    Messages:
    319
    Location:
    Long Beach CA
    190 appears way to high at cruise, not convinced the problem has been solved. My temps at cruise are around 175 on both engines. The thing that bugs me is early on you said the turbo hose blew off. I assume that is the approx 2" in raw water hose going into the dump can. That is symptomatic of the dump can being clogged. Not familiar with your aftermarket dump can, but mine had many small diameter holes which would be easy to clog with sea water debris and zincs. Certainly proceed with caution and maybe schedule to look at the can dump over the winter months.
  18. Boomer

    Boomer Senior Member

    Joined:
    Oct 14, 2017
    Messages:
    671
    Location:
    Seminole
    Air side, not the water side
    ..2 different issues
  19. cleanslate

    cleanslate Senior Member

    Joined:
    May 29, 2018
    Messages:
    1,385
    Location:
    Cherry Hill, NJ
    Yeah still a little to warm, ...did you do the heat exchanger in the tank?
    Other wise you may have to do another overnight soak with barnacle buster again. You definitely got some of the junk out on the first soak but you may have to do a second one as I said.
    The heat exchanger should look a worlds difference when you get it to the right person to have it cleaned out make sure you use somebody who knows what they're doing with a good reputation.
  20. Boomer

    Boomer Senior Member

    Joined:
    Oct 14, 2017
    Messages:
    671
    Location:
    Seminole
    Agreed...water cooling off in the gulf now...I should have no problem until winter when I pull them to get boiled...i know i am marginal currently but some of our best boating weather is.coming