2005 Pontiac Sunfire Owner's Manual - Page 231

Adding Coolant {CAUTION: Turning the surge tank pressure cap when the engine and radiator are hot can allow steam and scalding liquids to blow out and burn you badly. Never turn the surge tank pressure cap - even a little - when the engine and radiator are hot. The vehicle must be on a level surface. When your engine is cold, the coolant level should be at the FULL COLD mark. If the low coolant light comes on and stays on, it means you are low on engine coolant. See Low Coolant Warning Light on page 3-30. If you need more coolant, add the proper DEX-COOL® coolant mixture at the surge tank, but only when the engine is cool. If the surge tank is empty, a special fill procedure is necessary. See Engine Overheating on page 5-26 for instructions on "How to Add Coolant to the Coolant Surge Tank." {CAUTION: You can be burned if you spill coolant on hot engine parts. Coolant contains ethylene glycol, and it will burn if the engine parts are hot enough. Do not spill coolant on a hot engine. When replacing the pressure cap, make sure it is hand-tight. 5-25