Corrosion inside the cooling system can cause failure of various components such as thewater pump, thermostat, radiator cap and heater control valve. The best way to preventcorrosion is to flush the cooling system periodically and replace the antifreeze. If thecar has more than 60,000 miles, you should also consider replacing the thermostat andradiator cap preventatively. Some modern engines cannot tolerate even a single bout ofoverheating without incurring serious damage like a blown head gasket. So everything youcan do to prevent overheating is a plus.