1998 Pontiac Bonneville Owner's Manual - Page 274

Engine Coolant The cooling s stem in your vehicle is filled with DEX-COOL engine coolant. This coolant is designed to remainin your vehicle for 5 years or 150,000 miles (240 000 km) whichever occurs first, if you add only DEX-COOL' extended life coolant. NOTICE: When adding coolant,it is important that you use only DEX-COOL@(silicate-free) coolant. If coolant other than DEX-COOL is added to the system, premature engine, heater core or radiator corrosion may result. addition, the In will engine coolant require changesooner at 30,000 miles (50 000 km)or 24 months, whichever occurs first. Damage caused by the use of coolant otherthan DEX-COOL@i not s covered by your new vehicle warranty. 8 The following explains your cooling system and how to add coolant when it low. If you have a is problem with engine overheating, "Engine see Overheating" in the Index. A 50/50 mixture of water and DEX-COOL@ coolant will: 0 0 -- 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. 6-23