1997 Pontiac Bonneville Owner's Manual - Page 233
1997 Pontiac Bonneville Manual
Page 233 highlights
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 FULL COLD mark, add a 50/50 mixture of clean water (preferably distilled) and DEX-COOL@ (silicate-free) antifreeze at coolant recovery tank. (See the "Engine Coolant" in the Index for more information.) With plain water or the wrong your engine mix, you could get too hot but wouldn't get the overheat warning.Your engine could catch fire and you or otherscould be burned. Use a 50/58 mix of clean water and DEX-COOL@coolant. r--- Adding only plain water cooling system your to can be dangerous. Plain water, or some o'ther liquid like alcohol, boil before the proper can coolant mix will. Your vehicle's coolant warning system is set for the proper coolant mix, CAUTION: (Continued) 1 c NOTICE: In cold weather, water can freeze and crack the engine, radiator, heater core and other parts. Use the recommended coolant the proper and coolant mix. 5-20