Pontiac 1996 Grand Prix Owner's Manual page 213

3. After the engine cools, open the coolant
air
bleed valve.
I
3.4L V6 (VIN Code X):
There are
two
bleed valves.
They are located on the
thermostat housing and
heater inlet pipe.
The
.thermostat location is
shown here.
3.1L V6 (VIN Code M): There are two bleed valves.
One is
located on the thermostat housing. The other is
located on the thermostat bypass tube.
i
5-20