Volvo MD2030D Engine Coolent

About one to two cups full of

About one to two cups full of water coolent is blown out of the filler cap tube if the engine is run hard for about three hours. The engine as about 1000 hours on the clock is this normal?

"Keith,

Raw seawater is lea

"Keith,

Raw seawater is leaking internally past one of the neoprene rubber end caps (boots) that you see on both ends of the water reservoir, and is entering the fresh water-cooling circuit. You might need to tighten the hose clamps and/or replace one or both caps. You should also have a look at the exhaust elbow as the rather small nipple inlet for the hot raw water might be restricted - which would raise the raw water pressure and contribute to leaking. You should also consider draining the contaminated coolant, rinse the engine (taking care not to pressurize the exhaust elbow enough that you get water backwards past the valves into your cylinders), and replace the coolant-water mixture."

"Having trouble tracking down

"Having trouble tracking down a coolant leak on a Volvo MD2020. No sign of leak when running, but appears to lose about a pint of coolant into the sump under the engine on cool down."

"Bernard,

Very interesting.

"Bernard,

Very interesting. Just to clarify: the sump you refer to is external to the engine, a bilge sump, not the oil reservoir sump? "On cool down" means the engine is stopped, or is still running at low RPM after a previous run at normal operating temperatures?

Do you have to top-off or refill the coolant reservoir when this occurs – i.e. is raw water displacing coolant?"