Abstract: An engine cooling system for an automotive vehicle has a cross-flow fan driven by a motor coupled thereto for producing an air flow through a radiator disposed in front of the cross-flow fan. The cross-flow fan is housed in a casing assembly composed of an upper casing, a lower casing, and a pair of lateral casings for guiding the air flow through the cross-flow fan. The upper casing has a curved portion covering a portion of the cross-flow fan for preventing an air flow from counteracting rotation of the fan. Means may be provided for retractably covering the portion of the fan to prevent the counteracting air flow only when the automotive vehicle runs at a certain speed or higher. Such means comprises a triangular portion of the upper casing hinged for angular movement between a fan covering position and a position to define an additional air flow passage. Alternatively, the means comprises a coiled resilient member having one end retractably extending through the upper casing in the vicinity of the fan.