Volvo Forums - Volvo Enthusiasts Forum - 2019 Volvo V8-430-CE Overheating

Please help, my V8-430-CE-M overheats only when on the lake. With a gardenhose attached to either flush fitting it does not over heat. The first overheat disintegrated the impeller. I have disassembled and inspected the raw water pump housing and the heat exchanger, installed a new OEM impeller and disconnected and flushed all four hoses connected to the pump and the heat exchanger in both directions. It is not possible to mix up the reattachment of the hoses. I have inspected all four seals in both of the flush fitting caps. When the engine overheats the impeller housing and the heat exchanger get very hot. The coolant reservoir is topped off. When the garden hose is attached to the intake hose of the raw water pump, water runs freely out of the water pickup ports on the front of the outdrive, a DP 232 forward drive.

The water intake ports must be covered with tape when the engine runs on the flush fittings; if not the impeller housing heats up.

I used an old Volva-Penta-type out drive muff connected to the water intake ports on the outdrive and the impeller housing got hot.

I attached a garden hose to the output end of the pick up hose from the raw water pump and taped off the water pick up ports on the outdrive. Low water pressure blew the tape seal of course so I held it tight with my hands and saw no signs of leaking throughout the full pick up hose system.

I attached a one foot length of clear hose to the input port of the pump and submerged it in a one gallon bucket of water. The pump self primed and emptied the bucket in less than 5 seconds.