2002 Buick Regal Owner's Manual - Page 236

4. After the engine cools, open the coolant air bleed valve. There is one bleed valve. It is located on the thermostat housing. A. 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. B. If you have the supercharged engine, remove the nut in the center of the cover shield. C. Lift the engine cover shield at the front, slide the catch tab out of the engine bracket and remove the cover shield. D. Put the oil fill tube, with cap attached, in the valve cover oil fill hole until you're ready to replace the cover shield. 5. Fill the radiator with the proper DEX-COOLR coolant mixture, up to the base of the filler neck. See "Engine Coolant" in the Index for more information about the proper coolant mixture. 5-19