replaced attwod pump antifreeze is flowing good . sea water seems to be flowingthrough plexie glass engine runs cool at low rpm when crusing quickley heats up. any help with this would be great thanks for reading
Manifold elbows or heat exchanger check water temp on the discharge on heat exchanger should be hot not warm? if warm exchanger problems? check ends plates on exchanger might be pluged with zinks or trash?
Sounds like you have something sticking or wearing out in your cooling system. The best answer would be to take your question and/or boat to a marina or boat mechanic.
First check to see if water is coming out with your exhaust. That will confirm that your seawater pump is working. If there is no water in the exhaust, you need to replace the impeller or maybe the entire seawater pump. Then I would want to see if the thermostat is stuck closed. Next I would suspect the heat exchanger. They can clog and have to be tanked or rebuilt. Pull it off and take it to a radiator shop. The other possibility is that there is a blockage in one of the hoses. If one manifold is hotter than the other, that is what I would suspect.
