E 250 V10-6.8L VIN S (2005)
Thermostat: Testing and Inspection
Thermostat
A new thermostat should be installed only after the following electrical and mechanical tests have been carried out.
Thermostat-Mechanical Test
1. Remove the thermostat.
2. Check the thermostat for seating. Hold the thermostat up to a lighted background. Leakage of light around the thermostat valve at room
temperature indicates that a new thermostat should be installed. Some thermostats have a small leakage notch at one location on the perimeter of
the thermostat valve, which is considered normal.
3. Immerse the thermostat in a boiling antifreeze and water mixture.
4. See the General Specifications chart for thermostat opening temperatures.
