Thermostat Inspection

WARNING: This page is about a different car, the 2017 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

Remove the thermostat. (See THERMOSTAT REMOVAL/INSTALLATION .)
Visually check that the thermostat valve is closed.
Place the thermostat in water.
WARNING:
- During inspection, the thermostat and water are extremely hot and can cause severe burns. Do not touch the thermostat and water.
Heat the water and check the following.
- Opening temperature and valve lift
  - If there is a malfunction, replace the thermostat.
  Thermostat initial-opening temperature
  
  U.S.A. and Canada : 80.5-83.5 °C {177-182 °F}
  
  Except U.S.A. and Canada : 86.5-89.5 °C {188-193 °F}
  
  Thermostat full-open temperature
  
  95 °C {203 °F}
  
  Thermostat full-open lift
  
  U.S.A. and Canada: 8.5 mm {0.33 in} or more
  
  Except U.S.A. and Canada: 8.5-11.0 mm {0.34-0.43 in}