2003 GMC Safari Owner's Manual - Page 251

If there seems to be no leak, the engine again. start The engine cooling fan speed should increase when idle speed is doubled by pushing the accelerator pedal down. If it doesn't,yourvehicle needs service. Turn off the engine. - How to Add Coolant to the Coolant Recovery Tank If you haven't found a problem yet, but the coolant level isn't at the ADD mark, add a 50/50 mixture of clean drinkable water, and DEX-COOL@ engine coolant at the coolant recovery tank. See Engine Coolant on page 5-28 for more information. Notice: Engine damage from running your engine without coolant isn't covered by your warranty. Notice: When adding coolant, it is important that you use only DEX-COOL@ (silicate-free) coolant. If coolant other than DEX-COOL@ added to the is system, premature engine, heater core radiator or corrosion may result. In addition, the engine coolant will require change sooner at 30,000 miles (50 000 km) or24 months, whichever occurs first. Damage caused by the use of coolant other than DEX-COOL@ not covered by your new vehicle is warranty. 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 wouldn't 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 CQOL@coolant. 5-34