winterizing closed-loop system

[Scienceguy]

Hi All,


I've never winterized an inboard. So I need some affirmation.

This is a closed - loop system, so besides the heater hoses on the port engine, what else is there after you blow it out thoroughly with anti-freeze? I can't see where else there could be water. Am I correct on this?

I appreciate your thoughts.

[mjk1040]

Well you should drain your exhaust manifolds, heat exchangers, oil coolers, fresh water pump and mufflers. Then I would suggest filling them with -50 RV antifreeze by hooking the fresh water pump up to a 5 gallon can of RV antifreeze and running the engine until u have pink antifreeze coming out the exhaust. Check your manual or go on the Carver site and look up your manual. Just in case I missed something. Mike

[Scienceguy]

Hi Mike,

Why do you have to drain when you're using anti-freeze to push everything out?

[tomschauer]

You don't have to drain, but if you don't you will need to use more anti freeze as it will not just "push" the water out, it will mix with the water and dilute the antifreeze. You then need to run a few more gallons through to make certain you have sufficient protection.

[Viper]

If the manifolds are raw water cooled, drain them first. If you have mufflers that are not self draining, drain those as well. I do not recommend pumping antifreeze without draining the water first, not worth the risk IMO.

[Scienceguy]

OK.

Thanks guys!!