[eSailor]

Hello, I hope you all are able to get your boats launched this year and isolate on a cool breeze. Today was the first warm day in Maine, and the sailing was fine. I have a coolant mystery you all might be able to help with.

My beauty is a 1979 Pearson 28, with its companion, a trusty A4.
It equipped with a SenDure (3T122P5) Heat exchanger sending through a standard exhaust /sea water ejector (what are those called anyway?).
Sea water inlet has a filter and it was clear.

On starting the engine and running for 20 minutes, for the first time this season at anchor, I noticed that the exhaust had vapor in it for longer than usual and the the flow out the exhaust "seemed" low. Later after running under load, the engine overheated to 180 degF. The inlet cock is open, the hose to the 2 year old Moyer pump looks good. Engine coolant, glycol mix was good. Brand new pump there. So something is not right.

I guessing a heat exchanger obstruction, maybe old zinc crud?.
Any one else have any ideas or similar experiences?

Cheers,
es,
Dea Latis
Portland, Maine