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Cummins C series heat exchangers

Discussion in 'Engines' started by enproep, Jun 27, 2017.

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  1. enproep

    enproep New Member

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    Hello, I have twin Cummins C series diesel's in my motor yacht that are approx. 17 years old with only 950 hours on them. They run great, but I've recently noticed seawater dripping at the end cap of the port heat exchanger (1 drop every 5 to 10 seconds). My mechanic is recommending I replace both heat exchangers at a cost of $7400 for both including labor and coolant. My question is, does this seam reasonable? It does look like the ends of the heat exchanger tubes have been JB welded once before. Can the leak be patched again? What are the ramifications of letting it go for awhile. Heat exchangers, aftercoolers and transmissions were serviced 5 years ago (approx. 300 hrs ago). Thank you in advance for help/advice. Bob
  2. ESSRTEE8

    ESSRTEE8 Member

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    Do you trust your mechanic?

    Downside if they are bad is that you will destroy the motor when they do leak.

    Have them pulled, inspected and go from there.
  3. Fishtigua

    Fishtigua Senior Member

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    Pretty much what Ess says, get them pulled and inspected.

    I just wrote on the Volvo 330 thread about the same thing, almost (I'm a Cummins dealer/ex-Volvo dealer).

    Get them looked at by an experienced engineer and get an unbiased appraisal for repair or change.
  4. enproep

    enproep New Member

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    Thank you ESSRTEE8. So, it's probably not recommended to run them until I swap them out? Thinking of doing it myself as I found OEM exchangers for $1600 ea. and they look pretty easy to swap out.
  5. enproep

    enproep New Member

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    Thanks Fishtigua. Know any Cummins dealers in So Cal?
  6. Fishtigua

    Fishtigua Senior Member

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    Ha ha. I'm in the UK, bloody long shot! :D
  7. PacBlue

    PacBlue Senior Member

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    You have a host of reputable boatyards in your NB to contact and at the minimum, get a recommendation for Cummins service. Basin Marine and Newport Harbor just to name a few.

    There is Seaboard Marine in Oxnard that has published a lot of information on Cummins issues: https://www.sbmar.com/category/articles/marine-aftercoolers/
  8. enproep

    enproep New Member

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    Thanks PacBlue, will contact Seaboard.
  9. Fishtigua

    Fishtigua Senior Member

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    I have to say Seaboard are a mine of information and know B & C Cummins like a boss.

    Recommended!
  10. rcoff512

    rcoff512 Member

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  11. Norm Skipper

    Norm Skipper New Member

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    If you have not solved the problem. The Cummins C Series heat exchangers have removal plates at each end and can be resealed with new gaskets and seals ( the seal is for the center bolt ). Check the plates for cracks ... change the zinc while you are there. If there is not enough room to remove the plates you may need to remove the heat exchanger. You should not need to replace the heat exchanger.