An engine cooling system including a refrigerant circulation flow channel passing through an engine, an electric refrigerant pump, an electromagnetic valve arranged in the refrigerant circulation flow channel, and a control unit. In the engine cooling system, when the electric refrigerant pump is stopped and the voltage application to the electromagnetic valve is shut off when the electromagnetic valve is closed and the electric refrigerant pump is in operation, the voltage application to the electromagnetic valve is shut off when a first predetermined time period has passed after the electric refrigerant pump is stopped. When the engine is intermittently stopped during warming up of the engine, current application to the electromagnetic valve is shut off while the closed state of the electromagnetic valve is maintained.