1997 Pontiac Trans Sport Owner's Manual - Page 347

What to Use Use a mixture of one-half clean water (preferably distilled) and one-half DEX-COOL@ coolant which won't damage aluminumparts. If you use this mixture, you don't need to add anything else. NOTICE: If you use an improper coolant mix, your engine couldoverheat andbe badly damaged. The repaircost wouldn't be covered by your warranty. Too much water in themix can freeze and crack the engine, radiator, heater core and other parts. I you have to add coolant more than four times a year, f Adding only plain waterto your cooling system can be dangerous. Plain water, or some other liquid likealcohol, can boil before the proper coolant mix will. Your vehicle's coolant warning system is set for the proper coolant mix. With plain water or the wrong your engine could mix, get too hot but you wouldn't getthe overheat warning. Your engine couldcatch fire and you or others could beburned. Use a 50/50 mix of clean water andDEX-COOL@coolant. have your dealer check your cooling system. 1~ NOTICE: If you use the proper coolant, don't have to you add extra inhibitors or additives which claimto improve thesystem. These canbe harmful. 6-22