Location of thermostat

I don't know the specific location on this certain vehicle, but 99% of the time you can follow the upper radiator hose to the thermostat housing on the engine block and that's usually where its at.

It is in the block sort of. If it is like the 4.6 in the Caddy Deville, the housing where the hose from the radiator meets the block. It should be so simple if it is like the one on the 97 Deville. If not it is a real biotch!! According to what my son has told me about them he thought I had one. Anyway let's say you have the simple style, there will be the hose connection that bolts on to thermostat housing. Disconnect the hose, unbolt the hose connector, inside the housing is the thermostat, you will need the special tool to remove the thermostat. You can barrow one from the parts store when you get the new thermostat. Depending on where you buy your parts there's usually a $50 - 75 deposit more than what it cost to buy one. That tool will unthread the old thermostat from the housing. Turn the new one in by hand so you can feel if you are cross threading it. If you are crossed threading it you are going to feel resistance from the start. If you are not and it is threading smooth and easy as it should, turn the thermostat all the way in as far as you can by hand. Put on a thin coat of hi temp silicone gasket sealer on the housing and the hose connector, put your new gasket on the housing or the connector which ever you prefer bolt the hose connector back on the thermostat housing. Have a nice day!!!

Worst case scenario, the housing that the thermostat is inside of will have to be removed because of its design. There is no separate hose connector, it's all one piece. If there is a separate hose connector, it unbolts. See previous answer. I personally have never worked on the style where the whole housing has to be removed from the block. I have only worked with the simple style, easy-peasy!