Nasty Coolant

[fox islander]

I decided to change out my coolant yesterday (M25XP). I've had the boat only 4 months and you can eat off the engine, so i was kinda surprized by the nasty rusty slop I pulled out of there...very little antifreeze seemed to be present. I'm going to fill it back up with water and flush it out a couple of times...does anyone have a favorite additive to help with that process?Thanks

 

[Ed]

sounds like someone mixed types of antifreeze

I had mine changed by a mechanic who put in some universal stuff that should work with anything. I got a mess. took weeks to clean it all out.just keep changing it with water untill it is all clear then use the factory recomended antifreeze.

 

[Maine Sail]

It's always..

It's always possible you have a leak between the HX and the raw water allowing sea or fresh water into the engine. You can buy an antifreeze tester at an auto-parts store for about $2.00. If you put in fresh antifreeze, and take a base line with the tester, you can measure in the future, and compare to your base line, to see if it's becoming diluted with raw water..