Thermostat Inspection

Check that air bleed valve (1) of thermostat is clean.
Check that valve seat (2) is free from foreign matters.

Fig 1: Identifying Air Bleed Valve And Valve Seat
Courtesy of SUZUKI OF AMERICA CORP.
Check thermostat valve operation using the following procedures:
1. Immerse thermostat (1) in water, and heat water gradually.
2. Check that valve is operating with the following specifications:
  Temperature at which valve starts opening
  
  80 - 84 °C (176 - 183 °F)
  
  Temperature at which valve becomes fully open
  
  95 °C (203 °F)
  
  Thermostat valve lift
  
  More than 8 mm (0.3 in) at 95 °C (203 °F)

If thermostat valve does not open as specified above, or sticks in any position, replace it.

Fig 2: Checking Thermostat Valve Operation

Courtesy of SUZUKI OF AMERICA CORP.