2004 GMC Yukon Owner's Manual - Page 406

Engine Coolant The cooling system in your vehicle is filled with DEX-COOL® 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-COOL® 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 on page 5-31. A 50/50 mixture of clean, drinkable water and DEX-COOL® coolant will: • 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. Notice: Using coolant other than DEX-COOL® may cause premature engine, heater core or radiator corrosion. In addition, the engine coolant may require changing sooner, at 30,000 miles (50 000 km) or 24 months, whichever occurs first. Any repairs would not be covered by your warranty. Always use DEX-COOL® (silicate-free) coolant in your vehicle. What to Use Use a mixture of one-half clean, drinkable water and one-half DEX-COOL® coolant which won't damage aluminum parts. If you use this coolant mixture, you don't need to add anything else. {CAUTION: Adding only plain water to your cooling system can be dangerous. Plain water, or some other liquid such as alcohol, can boil before the proper coolant mixture will. Your vehicle's coolant warning system is set for the proper coolant mixture. With plain water or the wrong mixture, your engine could get too hot but you would not get the overheat warning. Your engine could catch fire and you or others could be burned. Use a 50/50 mixture of clean, drinkable water and DEX-COOL® coolant. 5-28