Abstract: An engine cooling system for cooling an internal combustion engine on a motor vehicle such as an automobile, for example, includes an engine stop detector for detecting when the operation of the engine is stopped, an oil temperature detector for detecting the temperature of lubricating oil in the engine, a controller responsive to signals from the engine stop detector and the oil temperature detector for ascertaining whether the temperature of the lubricating oil at the time the engine is stopped is in excess of a reference temperature or not and for issuing a control signal when the temperature of the lubricating oil exceeds the reference temperature, and a fan driver for driving an engine cooling fan in response to the control signal from the controller.