1993 Chevrolet Corvette Owner's Manual - Page 218

Adding only plain:water.to yam cooling system can be dangerous. Plain water, or some other .liquidlike alcohol, can boil before the proper coolant mix will. Your vehicle'scoolant warning system is set for the proper coolant mix. With plain water or the wrong mix, your engine could gettoo 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 mix of clean water and a proper antifreeze. You can'bebumed if you -spiU"CoolaZit hot engine parts. Coolant contains'ethylene glycol and it will burn the engine parts are hotenough. Don't spill coolant on a hot engine. . ' .if 3 When the coolant in the coolant recovery tank is at or above COLD, start your vehicle. If the overheat warning continues, there's one more thing you can try. You can add the proper coolant m x directly i to the coolant high fill reservoir, but be sure the cooling system is cool before you do it.