Pontiac 2008 Grand Prix Owner's Manual page 305

3.8L V6 Engine
3.2. Lift the engine cover at the front, slide the
catch tab out of the engine bracket and
remove the cover.
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.
Thermostat Housing
4. After the engine cools,
open the coolant air
bleed valve located on
the thermostat housing
near the upper
radiator hose.
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