Engine coolant leak

[yhc]

Good evening,

We ran both engines yesterday evening at the dock for about 15 minutes to just test them out and did not notice any problem. Then this am we noticed quite a bit of engine coolant under the starboard engine this morning. We refilled the coolant...just shy of a gallon and ran the engines for about an hour and did not have any problem...temp held at 80'C for both engines though the starboard engine warmed up a bit faster than the port engine. We will check them out again tomorrow morning to see whether there might be more leakage.

We recently had a Yanmar certified mechanic work on the engines for a routine 50 hour tune up, including coolant change, etc. We will check all the connectors, etc again but if you have any other thoughts or recommendations please do let me know.

Thanks for your time in advance.

Regards,

yhc

[yhc]

No new leaks noted today. Still a mystery as to how, where the leak is coming from when it happens.... It appears the leak only happens with the initial run after the engine has been laid up for a few weeks. If you have any thoughts/ideas, do let me know.

Regards,

yhc

[lpbp]

Air in system and out the vent when worked through . Kinda like a big burp.. Seen it before . 1 thought any ways

[yhc]

Thanks for the info, lpbp. We will keep an eye on it and see what happens.

P.S. It sounds more like a major GERD (a.k.a. reflux) rather than a burp! 8^)

[Russell]

Since this happens after the engine has been laid up for several weeks it might be a sticking thermostat. The engine overheats briefly but because there is no circulation it does not show on the temperature gauge. Then the thermostat opens with the high temperature and everything functions normally until the next layup.

[yhc]

I think we found the cause...one of the drain plug was ever so slightly loose. I tightened it up and will continue to watch but apparently it was more noticeable after a long lay up since it only drips so slowly....

We are off to Alaska through the Inside Passage now. We have been weathered in Cambell River, Canada.

Cheers!

yhc