1996 Buick Century Owner's Manual - Page 183

AC U-ION: How to Add Coolant to the Coolant Recovery Tank If you haven't found a problem yet, butthe coolant level isn't at ADD, add 50/50 mixture of clean water a (preferably distilled) andDEX-COOL(orange-colored, silicate-free) antifreeze at the coolant recovery tank. (See "Engine Coolant" in the Index for more information.) Heater and radiator hoses, and other engine parts, can be very hot. Don't touch them. If you do, you can be burned. Don't run the engine if there is a leak. If you run the engine, it could loseall coolant. That could cause an engine fire, and you could be burned. Get any leak fixed before you drive thevehicle. NOTICE: Engine damage from running your engine without coolant isn't coveredby your warranty. If there seems to be no leak, with the engine on,check to see if the electric engine fan is running.the engine is If overheating, the fan should running. If it isn't,your be vehicle needs service. Adding only plain water to your cooling system can be dangerous. Plain water, or some other liquid like alcohol,can boil beforethe proper coolant mix will. Your vehicle's coolant warning system is set forthe proper coolant mix. With plain water or the wrong mix, your engine could get too hot but you wouldn't get overheat the warning. Your engine could catch fire and you or others could beburned. Use a 50/50 mix of clean water and DEX-COOL antifreeze. TM 5-17