Mitsubishi S4S-D — Inspection of Thermostat
Maintenance · Cooling system
For the Mitsubishi S4S-D, from the Mitsubishi service manual.
Applies to: Mitsubishi S4S-D, Mitsubishi S4S engine
Before you start
- Stir the water in the container with a bar to ensure uniform temperature distribution.
Procedure
- Immerse the thermostat in a container filled with water.
- Heat the water while measuring the water temperature.
- Record the temperature at which the valve starts opening and at which valve lift becomes 9 mm or more.
- If temperatures are not within the standard range, replace the thermostat.
Specs & values
- Valve opening: 76.5 +/- 1.5 C [169.7 +/- 2.7 F]
- Valve lift 9 mm at approx 90 C [194 F]
Source: Mitsubishi service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.