How to Change the Thermostat in a Nissan Altima

The Altima sets itself apart from the pack by offering sporty handling with ample, refined power as well as a comfortable, pleasant interior. The third generation Altima (2002 to 2006) is in demand by used-vehicle buyers. The following information details the installation of a new thermostat in those models.

Things You'll Need

  • Mechanic's toolset, including a full socket set, wrenches and screwdrivers
  • Replacement thermostat, new or rebuilt
  • New gasket for thermostat
  • Drain the coolant from the radiator and store it in a proper container. Take the negative battery cable from the terminal.

  • Disconnect the radiator lower hose from the engine coolant inlet side. Take out the engine coolant inlet and the thermostat.

  • Install the new thermostat with the entire circumference of the flange fitting securely inside the rubber ring. Make sure the jiggle valve is facing up with a deviation of the position plus/minus 10 degrees.

  • Use Genuine RTV Silicone Sealant or an equivalent product when installing the temperature sensor for the engine coolant. Apply a mild detergent to the O-ring when setting the heater pipe into the housing.

  • Refill the cooling system with the appropriate type and amount of coolant. Reconnect the battery ground.

  • Start the engine and allow it to run for several minutes. Check the system for coolant leaks.