How to Replace the Thermostat in a 2000 Nissan Xterra

The thermostat in a 2000 Nissan Xterra opens up when the coolant reaches a predetermined temperature, which allows the coolant to circulate to the radiator. If the thermostat sticks open or closed, then the coolant won't be able to cool the engine properly, which can lead to an overheating condition. Should this happen, you can overheat the engine and cause serious damage. Before this happens, you should replace the thermostat, which will take about an hour.

Instructions

1

Let the engine in the Xterra cool for a few hours so you don't burn yourself. Put a drain pan below the radiator and open up the drain plug on the bottom of the radiator.

2

Remove the hose clamps securing the upper radiator hose to the thermostat housing using the flathead screwdriver, then remove the hose from the housing and the radiator. Repeat for the lower radiator hose.

3

Unbolt the fan shroud from the core support with the 3/8-inch ratchet and socket. Loosen the belt tensioner using the 3/8-inch breaker bar and a socket, then pull the belt off of the front of the engine. Unbolt the water inlet from the front of the engine using the 3/8-inch ratchet and socket. Pull off the water inlet and remove the thermostat from the housing.

4

Put a small bead of RTV sealant to the mounting surface on the water inlet. Insert the replacement thermostat onto the engine and reinstall the water inlet using the 3/8-inch ratchet and socket.

5

Reinstall the upper and lower radiator hoses to the water inlet housing and the radiator using the flathead screwdriver. Open the radiator cap. Fill the radiator with the 50-50 pre-diluted coolant.

6

Start the Xterra and turn the heater up to its highest position. Let the truck run for 10 minutes, then cool for another 30. Recheck the coolant level and fill as necessary.