The thermostat is located behind the thermostat housing on the center front of the engine at the very top. You should see two rubber hoses; one leading from the housing to the radiator and another leading from the housing to the firewall. These will be on the passenger side of the housing. On the driver side of the housing there will be a thermostat sensor. There are two 13mm bolts holding it in. You will need to remove the belt, which is tensioned by the alternator/ power steering chassis, also 13mm bolts.
Yes, you will need to purchase a gasket and some liquid gasket. RTV Gasket sealent, but not the kind that hardens. That kind has a tendency to crack and break in my exp.
1-Drain the coolant system via the radiator plug on the lower passenger side of the radiator.
2-Inspect the fluid for debris- this is important. If the fluid is heavily weighted by small metal shards or black specs, one of two things are happening; your hoses are gone, if not going, or your water pump is scraping the inside of the block and needs to be replaced. If the fluid is clear and good, save it for re-use.
3-Disconnect the hoses on the housing and unbolt the housing using a 13mm wrench or socket. Don't mind the sensor unless you plan on changing it, which I suggest when changing the thermostat anyway. It's cheap and easy since you're already there.
4-Remove the thermostat; this may take some prying. Clean both the block and the housing with a razor blade and be sure both are dry and debris free. Just be carefull not to mar the housing opening on the block in the process. Any knicks may interfere with the seating of the new gasket.
5-Apply RTV gasket sealer to your gasket on both sides. Be liberal, but stingy. You want to cover the gasket completely, but keep excess to a minimum, as you don't want this stuff getting into your radiator. A small clump now could cause big problems down the road.
6-Lightly coat the very edges of the thermostat with the RTV to get it to stick with the housing and gasket. Place the Housing in place and get your bolts in, tightening each about a turn at a time intermitantly. Don't squash the gasket on either side, as this could tear the gasket and you'll have to start back from step 4 plus drying time.
7-Replace your hoses and belt, and give the RTV about 2-6 hours to set up a bit before starting, depending on the package reccomendations.
Hope this helps.
