Originally Posted by Guy
After some rough sailing there is no water flow through the exhaust when you start the engine. I remove the outlet hose from the heat exchanger and get some flow, re-connect the hose and all is well. I have checked the hoses and the vented loop and all is well. The engine temp is fine when water is flowing. The amount of water coming from the exhaust seems normal when the system is working. The salt
water pump has a new impeller and cam.
This problem is new this for this cruise.
This is odd. I just read about something similar with the Sydney
Hobart in 1998. In the interview they reckoned the engine overheated as the pickup point was sucking air from time to time during the big waves.
When I read that I thought it was highly improbable, I would have thought the raw water pump
would have self primed again practically instantly, but could this be the case for you? When you say "rough sailing" is it possible the boat is healing over enough to suck air in to the pickup and if so, does this stop the water flow until you effectively bleed it again by removing the outlet hose and thus removing a bit of the head
or some minor back pressure?