Thermostat Inspection

• Make sure that air bleed valve (1) of thermostat is clean. Should this valve be clogged, engine would tend to overheat.
• Check to make sure that valve seat is free from foreign matters which would prevent valve from seating tight.
• Check thermostat seal (2) for breakage, deterioration or any other damage.
  Fig 1: Checking Thermostat Seal & Air Bleed Valve

  Courtesy of SUZUKI OF AMERICA CORP.
• Check thermostatic movement of wax pellet as follows:
  • Immerse thermostat (1) in water, and heat water gradually.
  • Check that valve starts to open at specific temperature.

Temperature at which valve begins to open 

80-84 °C (176-183 °F)

Temperature at which valve become fully open 

95-97 °C (203 °F)

Valve lift 

More than 8 mm at 95 °C (203 °F)

If valve starts to open at a temperature substantially below or above specific temperature, thermostat unit should be replaced with a new one. Such a unit, if reused, will bring about overcooling or overheating tendency.

Fig 2: Checking Thermostatic Movement Of Wax Pellet

Courtesy of SUZUKI OF AMERICA CORP.