2008 Saturn Astra Owner's Manual - Page 208

9-18 Vehicle Service and Care If no coolant is visible in the coolant reservoir, add coolant as follows: How to Add Coolant to the Coolant Reservoir Notice: This vehicle has a specific coolant fill procedure. Failure to follow this procedure could cause the engine to overheat and be severely damaged. If you have not found a problem yet, check to see if coolant is visible in the coolant reservoir. If coolant is visible but the coolant level is not at or above the KALT/COLD mark, add a 50/50 mixture of clean, drinkable water and DEX-COOL® coolant at the coolant reservoir, but be sure the cooling system, including the coolant reservoir pressure cap, is cool before you do it. See Engine Coolant on page 9-12 for more information. { CAUTION Adding only plain water to the cooling system can be dangerous. Plain water, or some other liquid such as alcohol, can boil before the proper coolant mixture will. The vehicle's coolant warning system is set for the proper coolant mixture. With plain water or the wrong mixture, the engine could get too hot but you would not get the overheat warning. The engine could catch fire and you or others could be burned. Use a 50/50 mixture of clean, drinkable water and DEX-COOL® coolant. Notice: In cold weather, water can freeze and crack the engine, radiator, heater core and other parts. Use the recommended coolant and the proper coolant mixture. { CAUTION Steam and scalding liquids from a hot cooling system can blow out and burn you badly. They are under pressure, and if you turn the coolant reservoir pressure cap - even a little - they can come out at high speed. Never turn the cap when the cooling system, including the coolant reservoir pressure cap, is hot. Wait for the cooling system and coolant reservoir pressure cap to cool if you ever have to turn the pressure cap.