Toyota 90916-A3002
Thermostat

A proper repair of the thermostat starts by emptying the engine coolant from the system. Service technicians must first remove the V-bank cover sub-assembly together with engine moving control rod, engine mounting control bracket and engine mounting bracket front No.1 LH. First disconnect the fan along with the generator V belt then remove the idler pulley sub-assembly No.2 before separating the radiator hose outlet. The removal of the water inlet requires first removing two bolts before extracting the thermostat. The inspection of the thermostat requires you to measure its valve opening temperature at 80 to 84 degrees Celsius (176 to 183 degrees Fahrenheit), and you should replace it if measurements indicate nonconformance. The thermostat needs replacement when the valve lift measurement at 95 degrees Celsius (203 degrees Fahrenheit) shows less than 7.7 mm (0.3031 in.) or when the valve remains open below 40 degrees Celsius (104 degrees Fahrenheit). Position the new gasket onto the thermostat while facing the jiggle valve upward before installation within a 10 degrees range. Mount the water inlet by applying 10 N m (102 kgf/cm, 7 ft. lbs.) torque before installing the radiator hose outlet and idler pulley sub-assembly No.2 and fan and generator V belt after which the engine mounting bracket front No.1 LH, engine mounting control bracket, and engine moving control rod should be installed. The last operational stage includes returning the V-bank cover sub-assembly and adding engine coolant while verifying no leakages develop.

Separate the radiator hose outlet.

Verify that the valve lift is 10 mm (0.39 inch) or more at 95°C (203°F) and ensure the valve is fully closed at temperatures below 77°C (171°F); replace the thermostat if any of these conditions are not met.

Place a new gasket onto the thermostat and ensure the jiggle valve is positioned upward, which can be adjusted within 10° on either side of the prescribed position.

Install the water inlet with a torque of 10 Nm (102 kgf-cm, 7 ft. lbs.).

Remove the front wheel opening extension pads on both the left and right sides.

Take out the 2 bolts and the water inlet itself.

Install the water inlet using the 2 nuts, applying a torque of 9.0 Nm (92 kgf-cm, 80 in-lbf).

Remove the thermostat and take off the gasket from it.

The jiggle valve can be adjusted within 10° on either side of the indicated position.

Remove the water inlet by taking off the 2 nuts securing it.

Remove the water inlet by taking off the 2 nuts and disconnecting it from the cylinder block.

Take off the V-bank cover sub-assembly.

Place a new gasket on the thermostat and install it with the jiggle valve facing up, allowing for a 10° variance.

Reconnect the No. 2 radiator hose, add engine coolant, and inspect for any coolant leaks.

Remove the thermostat and the gasket from the thermostat.

Reinstall the water inlet using the 2 nuts, torquing them to 9.0 Nm (92 kgf-cm, 80 inch lbs.), then connect the No. 2 radiator hose.

Remove the radiator support opening cover and disconnect the No. 2 radiator hose.

Disconnect the No. 2 radiator hose.

Take off the V-ribbed belt.

Attach the water inlet using the 2 nuts, torquing them to 10 Nm (102 kgf-cm, 7ft-lbf).

The idler pulley cover plate diameter is 33.6 mm (1.32 in.) and the No. 2 idler pulley cover plate diameter is 37.8 mm (1.49 in.).