Section 205 (Engine Cooling System): Thermostat: Inspection

WARNING: This page is about a different car, the 2008 Toyota Yaris. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT THERMOSTAT
HINT:

The valve opening temperature is inscribed on the thermostat.

Fig 1: Identifying Thermostat Valve Opening Temperature
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. Immerse the thermostat in water and gradually heat the water.
2. Check the valve opening temperature of the thermostat.
  Valve opening temperature: 80 to 84°C (176 to 183°F)
  
  If the valve opening temperature is not as specified, replace the thermostat.
  
  Fig 2: Immersing Thermostat In Water
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Check the valve lift.
  Valve lift: 8.5 mm (0.335 in.) or more at 95°C (203°F)
  
  If the valve lift is not as specified, replace the thermostat.
4. Check that the valve is fully closed when the thermostat is at low temperatures (below 77°C (171°F))
  If not fully closed, replace the thermostat.
  
  Fig 3: Checking Valve Lift
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002