Hello guys and gals.

I have a sludge problem caused by a previousy cracked cylinder head. The head and leak it had have been repaired but I have yet to find a good way to lose all the sludge in the closed keel coolant system. It clings to all parts and heaps up in the heat exchanger when it gets loose.

When I replaced the cylinder head and gasket I flushed the system with canal water and a large sump pump for up to 15m which didn't help much.. then filled coolant until it had leaked out most of the water in the system and checked frost point for the fluid after running the engine and mixing up the fluids.

Usually I would just add flushing fluid or degreaser to flush it out like with regular cars but I have now way of emptying the system reliably without having to dump it via bilge pump or similar. And coolant is expensive as well.

Has anyone else found a way to do this better? The stuff is preventing proper cooling so the engine overheats if I'm not careful. Also thinking of adding a extra heat exchanger in the system to help cool when it gets hotter then intended.