Hi,
If you are looking for the thermostat for the cooling system, it is located very close to the throttle body assembly. There are some pictures of the general area at the link I have provided. These pictures show where the bleed valves are located, and if you follow the radiator hose near the throttle body, you will find the thermostat housing. The thermostat is kind of a pain to change on these particular vehicles because of the tight space involved.
Good Luck, Greg