1993 Pontiac Bonneville Owner's Manual - Page 206

If there seems to beno leak, check to see if the electric engine is running. fan If engine the is overheating, the fan should be running.If it isn't, your vehicle needs service. How to Add Coolant to the Coolant Recovery Tank: If you haven't found a problem yet, but the coolant level isn't up to the FULL COLD mark, add a 50/50 mixture of clean water (preferably distilled) and a proper antifreeze at the coolant recovery tank. See the Index under Coolant for more information about the proper coolant mix. I b-AuI IUN ,k I dangerous. Plain water, or some other liquid like alcohol, can boil before the proper coolant mix will. Your vehicle's coolant warning system is set for the proper coolant I mix. With plain wateror the When the coolant in the coolant tank is at or above FULL wrong mix, Your engine couldgetrecovery too hot but you wouldn't get the COLD, start your vehicle. If the overheat warning. Your engine overheat warning continues, there's one could catch fm and you or others more thing you can try. You can add the be Use a mix proper coolant mix directly to the of clean water and a proper radiator, but be sure thecooling system antifreeze. is cool beforeyou do it. Adding only plain water to L your cooling system can be You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol and it will burnif the engine parts are hot enough. Don't spill coolant on a hot engine. L r In coldweather,watercanfreeze and crack the engine, radiator, heater core and other parts. Use the recommended coolant. II I 205 "