Abstract: A protective cover for use on motor vehicle radiators while the vehicle is being serviced, fits over a radiator to protect it from damage which might otherwise be caused by inadvertent impact of a tool or engine component being removed or replaced, and to protect hands and other body parts of service personnel from cuts resulting from contact with sharp heat exchanger core fins of the radiator, or burns resulting from contact with hot radiator components, comprises a flexible pad having a front section that is adapted to lie on and remain in place on the upper tank portion of a radiator, and a rear core section adapted to drape downwards from the front tank section, over the heat exchanger core section of a radiator. Transversely disposed, sealed tubular weight-containing pockets are provided near the front peripheral edge of the cover, to maintain the tank portion of the cover in place by the force of gravity.