Cooling system question

[Crustycritter]

I have a twin crusader inboards, with FWC. The port engine temp never raises at all but on long runs some of the coolant is backing out of the overflow tube. Could it be a heat exchanger problem? :shrug:

[Keta]

Start by replacing the fill cap on the heat exchanger.

[troutdaddy]

I had a similar issue with my inboard. No overheating at speed, but the burp tank would spew frothy coolant atspeed. The cure..not obvious. Add more coolant. The deficit was liquid coolant causing a build-up of pressure in the system when it got heated up. I was also occasionally getting warm at idle, but not at speed. In my case the system was underfilled from the factory, but you may have lost some from poor fitting cap as well. Have you checked the level

[Flush Release]

Do you have a recovery tank? What you are dealing with is expansion of your coolant and the reliefs on you radiator cap. If you don't have a makeup tank installed you may want to.