== Don't know ==
'''where the thermostat belongs, but it should go back where and the direction it came out! '''
You need the [http://www.partstrain.com/ShopByDepartment/Engine/Thermostat_Housing/Toyota?source=adwords3&ef_id=SwhEntBkLCYAABV6KusAAAJA:20101109022621:s|exact model and year] ''(there's at least four posiblities)'' of your car to find the correct directions.
These directions are typical:
# Clean off old gasket material, rust or scale
# Use a new gasket
# Install the thermostat into the housing in the same direction that the old thermostat was in. Then install the housing in place on the engine and tighten its bolts/screws.
# Re-install all the other parts and components in the reverse order of removal. On V6 engines, you'll need a new O-ring on the water inlet pipe; lubricate this O-ring with soapy water.
# Refill the engine coolant, making sure the drain plug is re-installed and '''the heater control is at the maximum heat position. Use fresh coolant''' if the old coolant is dirty or contaminated in any way; use a 50/50 mixture of coolant and water.
# '''Run the engine in a well-ventilated area with the radiator cap off until the thermostat opens; the coolant will start flowing and the upper radiator hose will get hot. Shut off the engine, wait for it to cool and more coolant mixture until it reaches the radiator filler neck lip.'''
# '''Bleed air from the cooling system on a V6 engine by squeezing the upper radiator hose;''' wear gloves when you do this, as the hose will be hot. Add more coolant as needed.
'''Remember to return and mark accepted the answer that best solves your problem'''.
Good luck,
N