Pontiac 2004 Bonneville Owner's Manual page 312

2. Then keep turning the pressure cap, but now push
down as you turn it. Remove the pressure cap.
3. Remove the 3800 Series II V6 engine cover shield
to access the bleed valve.
5-36
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.
3.2. Lift the engine cover shield at the front, slide
the catch tab out of the engine bracket and
remove the cover shield.
3.3. Put the oil fill tube, with cap attached, in the
valve cover oil fill hole until you are ready to
replace the cover shield.