1998 Pontiac Bonneville Owner's Manual - Page 232

How to Add Coolant to the Coolant Recovery Tank I NOTICE: If you haven't found a problem yet, but the coolant level In cold weather, water freeze and crack can isn't at the FULL COLD mark, add50/50 mixture of a the engine, radiator, heater core andother parts. clean water (preferably distilled) and DEX-COOL@ Use the recommended coolant and proper the engine coolant at coolant recovery tank. (See the coolant mixture. "Engine Coolant" in the Index more information.) for I A CAUTION: ~ Adding only plain water your cooling system to can be dangerous. Plain water, some other or liquid like alcohol, can boil beforeproper the coolant mixturewill. Your vehicle'scoolant warning system is set the proper coolant for mixture. With plain water the wrong mixture, or 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 water and DEX-COOL@coolant. 5-19