OEM 2000 Toyota Sienna Thermostat

2000 Toyota Sienna Parts Questions & Experts Answers

• Q: How to service and repair the thermostat on 2000 Toyota Sienna?

  A: Service and repair of the thermostat begins with draining engine coolant from the system. First disconnect the components of air cleaner cap and its hose from the ECT switch connectors and engine wire protector from water inlet and right cylinder head by loosening 2 nuts. Begin by disconnecting the water inlet pipe from the water inlet and left cylinder head while removing its bolt together with the O-ring on the inlet pipe. The water inlet and thermostat removal process begins by taking away the 3 nuts securing the thermostat while removing its gasket. Thermostat inspection requires submerging it in water while heating at a gradual pace to verify the open valve temperature between 80 - 84 degrees Celsius (176 - 183 degrees Fahrenheit); a replacement thermostat should be used in case the value falls outside this range. To ensure proper function the valve must have a lift of 10.0 mm (0.394 inch) at 95 degrees Celsius (203 degrees Fahrenheit) while remaining fully closed below 40 degrees Celsius (104 degrees Fahrenheit); get a replacement if necessary. Place the thermostat inside the water pump while using a new gasket and position its jiggle valve toward the upper stud bolt. Connect the water inlet pipe first by applying soapy water then secure it to the water inlet before tightening the bolt up to 19.5 Nm (200 kgf-cm, 14 ft. lbs.). Before connection install a new O-ring on the water inlet pipe. Begin by putting back the engine wire protector and connecting ECT switch connectors then reinstalling the air cleaner cap along with its air cleaner hose. Start by filling the engine with coolant then start the vehicle before searching for any fluid leaks and verifying the engine coolant measurement.