2008 Pontiac Grand Prix Owner's Manual - Page 308

How to Add Coolant to the Cooling System (5.3L V8 Engine) Notice: The engine has a specific cooling system drain and fill procedure. Failure to follow this procedure could cause the engine to overheat and be severely damaged. If the engine's cooling system needs to be drained and re-filled, please see the dealer/retailer. You can remove the pressure cap when the cooling system, including the pressure cap and upper radiator hose is no longer hot. Turn the pressure cap slowly counterclockwise. {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. Fill the cooling system with the proper DEX-COOL® coolant mixture, up to the base of the filler neck. See Engine Coolant on page 5-24 for more information about the proper coolant mixture. 4. Rinse or wipe any spilled coolant from the engine and the compartment. 5. Then fill the coolant recovery tank to the COLD FILL line. 6. Install the coolant recovery tank cap and the pressure cap. 1. If you hear a hiss, wait for that to stop. A hiss means that there is still some pressure left. 2. Then keep turning the pressure cap to remove the pressure cap. 7. If the coolant in the recovery tank is constantly low, you should have a dealer/retailer service department inspect your vehicle for leaks. 5-38