1999 Cadillac Catera Owner's Manual - Page 258

yellowblue Surge Tank Pressure Cap NOTICE: The surge tank cap is a 14 psi (97 kPa) pressure-type cap and must be tightly installed to prevent coolant loss and possible engine damage from overheating. If the surge tank pressure cap needs to be replaced, a GM cap is recommended. Engine Coolant The cooling system in your vehicle is filled with DEX-COOLR engine coolant. This coolant is designed to remain in your vehicle for 5 years or 150,000 miles (240 000 km), whichever occurs first, if you add only DEX-COOLR extended life coolant. The following explains your cooling system and how to add coolant when it is low. If you have a problem with engine overheating, see "Engine Overheating" in the Index. A 50/50 mixture of clean, drinkable water and DEX-COOLR coolant will: Thermostat Engine coolant temperature is controlled by a thermostat in the engine coolant system. The thermostat stops the flow of coolant through the radiator until the coolant reaches a preset temperature. If the thermostat needs to be replaced, a GM thermostat is recommended. D D D D D Give freezing protection down to -34_F (-37_C). Give boiling protection up to 265_F (129_C). Protect against rust and corrosion. Help keep the proper engine temperature. Let the warning lights and gages work as they should. 6-20