2008 Pontiac Grand Prix Owner's Manual - Page 304

How to Add Coolant to the Radiator (3.8L V6 Engine) Notice: Your engine has a specific radiator fill procedure. Failure to follow this procedure could cause your engine to overheat and be severely damaged. 2. Then keep turning the pressure cap and remove it. {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. 3. Remove the engine cover to access the bleed valve. 3.1. Clean the area around the engine oil fill tube and cap before removing. Twist the oil fill tube, with cap attached, counterclockwise and remove it. 3.8L V6 Engine 1. You can remove the pressure cap when the cooling system, including the pressure cap and upper radiator hose, is no longer hot. Turn the cap slowly counterclockwise. If you hear a hiss, wait for that to stop. A hiss means there is still some pressure left. 5-34