Over heating Not sure. Just overheating.checked thermostat.

Try this procedure:

• The thermostat can be stuck close. If you feel the upper hose very hot and the lower hose cooler than normal, it may be a stuck thermostat.

• Make sure the radiator and the overflow bottle are filled to the proper levels.

• Bleed air from the coolant system:This is best done by running the engine with the radiator cap off until you see when the air bubbles stop coming up.

• Check the radiator fans: The easiest way is to turn on the cars air conditioner and turn up the A/C fans. Both radiator fans should come on when the A/C starts

• Make a pressure test by using a pressure testing tool (available at most auto parts stores). Use the pressure shown on your radiator cap. Most cars are 16 PSI or less, so don't exceed that pressure. Replace the radiator cap if it doesn't hold the pressure.

Check your heater core check to see if floor is wet at all on passenger side

Need more info...
radiator fluid leaking?
rad fluid full when cold?
do you use distilled water or tap when filling radiator?
how long from cold start until overheat?
where are you located or what is outside temp? altitude?
are the hoses bulging?
oil in the rad fluid?
rad fluid in oil?!?!?
when last time rad flush and history of flushes?
has water pump ever been changed?
water pump making noise?
how many miles on engine?
any major work done on engine lately? at all?

How did you check thermostat? Did you check coolant level. Is the auxiliary water pump leakinh