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  1. #1

    Default half of engine runs warm

    I have a Gray Marine Engine in my 1965 Lyman - a CH175 that I've just replaced the port side head which was cracked. Also replaced thermostats and relief valves in both heads and a new water pump impeller. The starboard side of the engine runs at the proper temperature with 140 degree thermostats utilizing an infrared temperature gun. The port side where the head was replaced runs hot. Replaced head was machined and a valve job was performed and new valve seals installed. Can't understand why temperature is different on one side of the block than the other. Water flows through both exhaust pipes. Any ideas on why this is happening, I'm stumped?

  2. #2
    Join Date
    Mar 2009
    Portland, Oregon,

    Default Re: half of engine runs warm

    One logical explanation might be an incorrect head gasket pertaining to the openings for the coolant passages.
    Rick ... aka Ricardo..... AQ series Volvo Penta repair
    Portland, Oregon
    28' SDN F/B w/ twin Volvo Penta 5.7L DP drives

    "Intellectual growth should commence at birth and cease only at death." Albert Einstein

    Please... no PMs! Post your questions on the forum.

  3. #3

    Default Re: half of engine runs warm

    I had the same problem I took the water pump apart there was impeller pieces crammed in in one of the output passages. it was a job to dig the rubber out.

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