Northern Lights Genset - Losing Coolant

[BuoyScout]

Our genset is losing about a half cup of coolant per hour of runtime. I can't find any evidence of coolant leaking under the genny, so I'm guessing it going out with the seawater/exhaust?

History (that may help to diagnose):

- After being on the hard for the Canadian winter, the oil filter seal failed and drained out completely in the pan. After cleaning and replacing, I ran the genset once and it shut down after a few minutes. Checked oil and ran it again and it shut down again after a few minutes. At this point, I checked the coolant and it was bone dry - so it was auto-shutting down because it was overheating. I flushed the heat exchanger with distilled and refilled with coolant. Everything is now running fine, but coolant is being consistently consumed as mentioned.

Any recos for troubleshooting??? Much appreciated!

[duetto]

probably want to do a pressure test on your coolant/"radiator" cap. if you're losing pressure then next i'd isolate the heat exchanger and pressure test it. i don't have a northern lights so i don't know physically how to do it. if the he is ok, then i'd do a cylinder compression test.

you didn't say if coolant froze over the winter.

[BuoyScout]

Thanks for that! I'll let you know how the pressure testing goes.

(Not sure if the coolant froze over the winter)