I am in the process of overhauling the cooling system on my circa 1983 Yanmar 3QM30. It is designed as a raw-water cooled engine - heavier castings, zinc anodes, etc. - but was supplied from Hunter with a closed-loop glycol cooling system, a Sendure heat exchanger, and a separate Jabsco salt water pump - so none of the engine actually sees salt water. I have just replaced both water pump impellers, all the hoses, and have overhauled the heat exchanger. I put a wrench on the anode plugs on the engine, but they are not going to budge without considerable persuasion. I am not going to try and replace the engine anodes. After all, automotive diesels don't use anodes in their glycol cooling systems; they rely on the corrosion inhibitors included in the coolant chemistry. Why should it be any different for my Yanmar?
...And yes, I did put a new pencil anode in the Sendure heat exchanger, the only part of the system that sees salt water.
...And yes, I did put a new pencil anode in the Sendure heat exchanger, the only part of the system that sees salt water.
