Thermostat Check

Immerse the thermostat in water, and heat the water while stirring. Check the thermostat valve opening temperature.
Standard value:

87 ± 1.5°C (189 ± 3°F) < 2.0L ENGINE Non-turbo, 2.4L ENGINE >

76.5 ± 1.5°C (170 ± 3°F) < 2.0L ENGINE Turbo >

Fig 1: Checking Thermostat Operation
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Check that the amount of valve lift is at the standard value when the water is at the full-opening temperature.
NOTE: Measure the valve height when the thermostat is fully closed, and use this measurement to compare the valve height when the thermostat is fully open.

Standard value:

Full-opening temperature:

95°C (203°F) < 2.0L ENGINE Non-turbo, 2.4L ENGINE >

90°C (194°F) < 2.0L ENGINE Turbo >

Amount of valve lift: 8.5 mm (0.33 inch) or more

Fig 2: Measuring Thermostat Valve Height
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.