The Volvo Md11 has a Swedish built fresh water cooling system installed at build. Preferable to raw or sea water cooled. Circulation in the primary (around the engine block) is induced by a magnetically driven sealless pump. My initial diagnosis of the problem led me to believe the problem lay in the secondary or raw water side of the system. Changed impeller, suspected faulty indication, planned to back flush system or use central heating cleaning fluid. Anyway a quick WhatsApp to Hoffman Welding in Workum and Jacob came back with what is probably the cause.
