On goes my never ending saga with this
engine. This year it was the
heat exchanger. Then the starter died en
route to Figawi and I had to change in 40kt winds at midnight on
mooring night before
race. Only saving graceto that was winning the fleet.
Anyways I had an overhead
alarm after an extended motoring session. Anchored and what I found was all, or a lot, of
coolant pushed out of
exhaust manifold into overflow. This has happened before but never overheat. It must drain back when cool.
So I changed the thermostat and checked the old one was fine. Strainer is clean, pumps
raw water like a champ.
It will run for about 5-7 hours. The only "fix" is to pop the radiator cap and let the
coolant drain back in. I learned this trick yesterday just as I was about to negotiate woods hole and the
alarm went off.
Here's another strong clue. It bubbles, extremely vigorously, into overflow bottle. It has always done thisto some degree. So something is pressurizing the coolant out of manifold. At times it's a tiny like early in season or last year. Now it's almost like the overflow bottle is literally boiling.
My first thought is
head gasket. And the green prestone has taken on a dirtier color. But could the cap cause this too? Certainly the cheaper option.
Thx