Celica GT-S L4-1.8L (2ZZ-GE) (2000)
a. Immerse the thermostat in water and gradually heat the water.
b. Check the valve opening temperature.
Valve opening temperature: 80.0 - 84.0° C (176 - 183° F)
If the valve opening temperature is not as specified, replace the thermostat.
c. Check the valve lift.
Valve lift: 10 mm (0.39 inch) or more at 90° C (194° F)
If the valve lift is not as specified, replace the thermostat.
d. Check that the valve is fully closed when the thermostat is at low temperatures (below 40° C (104° F)).
If not closed, replace the thermostat.