OEM 2002 Toyota Sienna Thermostat

2002 Toyota Sienna Parts Questions & Experts Answers

• Q: How to service the thermostat on 2002 Toyota Sienna?

  A: The thermostat service requires draining engine coolant followed by disconnecting the air cleaner cap along with its hose. Disconnecting the ECT switch connectors together with engine wire protector requires unfastening two nuts from the water inlet and right cylinder head. The service begins by removing the bolt alongside the O-ring from the water inlet pipe while disconnecting the pipe from the water inlet and left cylinder head. You must remove all components from the water inlet and thermostat through the process of removing three nuts and the gasket which covers the thermostat. To inspect the thermostat place it in water while increasing the temperature and verify that it opens at 80 - 84 degrees Celsius (176 - 183 degrees Fahrenheit) while lifting up to 10.0 mm (0.394 inch) at 95 degrees Celsius (203 degrees Fahrenheit). Maintain total closure of the valve whenever the temperature descends beneath 40 degrees Celsius (104 degrees Fahrenheit). A thermostat replacement should occur whenever any established specifications prove unattainable. Install the new gasket between the thermostat and water pump before setting it in place with the jiggle valve touching the upper stud bolt. Place the new O-ring on the water inlet pipe by applying soapy water first before you install the pipe to the water inlet by using a bolt torqued to 19.5 Nm (200 kgf-cm, 14 ft. lbs.). After installation of the engine wire protector the technician should attach the ECT switch connectors before reinstalling air cleaner cap with connected air cleaner hose. Engine coolant filling should be followed by engine start-up then leak checking and a final check of the engine coolant level.