Locate the thermostat housing. The thermostat housing is located on the engine block, near the upper radiator hose.
Remove the bolts that hold the thermostat housing in place. These bolts are usually made of 10mm hex head bolts.
Remove the thermostat housing and old thermostat. Be careful not to spill any coolant when removing the thermostat housing.
Replace the old thermostat with a new one.
Make sure that the new thermostat is properly seated in the thermostat housing.
Install the thermostat housing and bolts. Tighten the bolts to 20 ft-lb.
Fill the radiator with coolant. Start the engine and let it run for a few minutes. Check for leaks and make sure that the coolant is circulating properly.
The thermostat on a 2004 Dodge Durango is located on the front of the engine, just below the upper radiator hose. It is a round, metal housing with two bolts holding it in place.
