Engine temp gauge sensor for E-Class (124)
Except for the difference in sensor location on the 104 engine vs the 103, I believe the temp gauge system is the same on your car as any other 124. You should be able to use the procedure and values that I provided above to locate, test, and calibrate engine temperature with your instrument gauge.
Be sure to locate the correct sensor for your purpose - you do NOT want the sensors that control the fuel system or fans (B10/11/12). There is a *separate* sensor for the gauge (B13). Btw, I suspect S-Class and others of the same vintage use the same system (and probably the same values), but I have not checked that.