OEM 2001 Toyota Sienna Thermostat

2001 Toyota Sienna Parts Questions & Experts Answers

• Q: How to service the thermostat on 2001 Toyota Sienna?

  A: The engine coolant needs to be drained before starting the thermostat service. Start service on the thermostat by first removing the air cleaner cap and air cleaner hose before disconnecting the ECT switch connectors and engine wire protector from the water inlet and right cylinder head while taking off their 2 nuts. Service the thermostat by first removing the bolt from the water inlet pipe and its O-ring along with the pipe from the water inlet and left cylinder head. Pipe out the water inlet and thermostat by unfastening all 3 nuts with their accompanying gasket. A proper inspection of the thermostat requires submerging it in water before heating it gradually to monitor the valve opening opens between 80 - 84 degrees Celsius (176 - 183 degrees Fahrenheit); faulty parts need replacement. It is essential to check that the valve achieves a minimum lift of 10.0 mm (0.394 inch) when operating at 95 degrees Celsius (203 degrees Fahrenheit and shows complete closure below 40 degrees Celsius (104 degrees Fahrenheit). If these requirements are not met, the valve needs replacement. When placing the thermostat into the water pump you should use a new gasket and set the jiggle valve correctly before engaging the upper stud bolt. The installation of the water inlet includes tightening the three nuts to 8.0 Nm (80 kgf-cm, 69 inch lbs.) while you apply soapy water to the new O-ring positioned on the water inlet pipe before connecting it to the cylinder head using the bolt and torquing to 19.5 Nm (200 kgf-cm, 14 ft. lbs.). The procedure requires engine wire protector reinstallation followed by ECT switch connector assembly then reinstalling the air cleaner cap with the hose and filling with coolant before starting the engine for leak checking and ending with radiator coolant verification.