2007 Pontiac Grand Prix Owner's Manual - Page 374

12. Then replace the pressure cap. At any time during this procedure if coolant begins to flow out of the filler neck, reinstall the pressure cap. Be sure the pressure cap is hand-tight and fully seated. 13. Check the coolant in the recovery tank. The level in the coolant recovery tank should be at the cold fill line when the engine is cold. How to Add Coolant to the Cooling System (5.3L V8 Engine) 3800 V6 Supercharged Engine shown, 3800 V6 Engine similar 10. Start the engine and let it run until you can feel the upper radiator hose getting hot. Watch out for the engine cooling fan(s). 11. By this time, the coolant level inside the radiator filler neck may be lower. If the level is lower, add more of the proper DEX-COOL® coolant mixture through the filler neck until the level reaches the base of the filler neck. Notice: Your engine has a specific cooling system drain and fill procedure. Failure to follow this procedure could cause your engine to overheat and be severely damaged. If your engine's cooling system needs to be drained and re-filled, please see your dealer. 374