The thermostat is used to control the flow of engine coolant. When
the engine is cold, the thermostat is closed to prevent coolant from
circulating through the engine. As the engine begins to warm up, the
thermostat opens to allow the coolant to flow through the radiator and
cool the engine to its normal operating temperature. Fuel economy and
engine durability is increased when operated at normal operating
REMOVAL & INSTALLATION
Never open, service or drain the radiator or cooling system when
hot; the system is under pressure and will release scalding hot coolant
and steam which can cause severe burns and other bodily harm. Also, when
draining engine coolant, keep in mind that cats and dogs are attracted
to ethylene glycol antifreeze and could drink any that is left in an
uncovered container or in puddles on the ground. This will prove fatal
in sufficient quantities. Always drain coolant into a sealable
container. Coolant should be reused unless it is contaminated or is
several years old.
If necessary, unfasten the retainer and remove the upper engine cover.
Disconnect the negative battery cable.
Remove the air cleaner and duct assembly.
Partially drain the engine cooling system, into a suitable container, to a level below the thermostat.
Disconnect the upper radiator hose from the water outlet.
If necessary, detach the electrical connections from the throttle body assembly.
Unfasten the water outlet attaching bolts, then remove the water outlet.
Remove the thermostat. Remove and discard the gasket.
Thoroughly clean the manifold water inlet and water outlet mating
surfaces. Inspect the water outlet for corrosion or other damage, and
replace if necessary.
Fig. 8: Exploded view of the thermostat and housing assembly - 3.8L (VIN C) engine
Fig. 9: Thermostat and water outlet mounting - 3.8L (VIN L) engine shown
Fig. 10: Exploded view of the thermostat, gasket and housing assembly - 1997 vehicle shown
Position the thermostat into the intake manifold with a new gasket.
Install the water outlet to the intake manifold with RTV sealer. Tighten the attaching bolts to 20 ft. lbs. (27 Nm).
Connect the radiator hose to the water outlet housing.
If necessary, attach the electrical connections to the throttle body assembly.
Install the air cleaner assembly, then connect the negative battery cable.
Refill the engine with the specified type and amount of engine coolant. Start the engine and check for coolant leaks.
I hope this helps; remember to rate this post. Good luck.