I don't know where the tstat is located in your car but in mine (M104) is where the upper radiator hose conects to the engine block. You just need to remove 3 bolts, replace the thermostat and o-ring and close it again. Pay atention to the thermostat position. It can be installed backwards.

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Juan
1995 E320 Sedan
2008 Ford Escape
RC Helicopter