18—120 Checking thermostat in oil filter

Special tool

Telethermometer for measuring engine                                                                                 
oil temperature
116 58g 2? ^ QQ
om617 - 0414-1.jpg


To obtain a favorable operating temperature of engine oil at a faster rate, a thermostat with an opening tem­perature of 110 °C (formerly 95 °C), part No. 117 180 00 75 has been installed in oil filter since December 1979.

The thermostat 110 °C can also be installed in engines manufactured at an earlier date as a spare part.

Start of series

Model                   Engine                  Engine end No.

116.120                617.950               019719


1    Exchange oil dipstick for flexible heat sensor.
2    Run engine at increased speed and watch tele-thermometer.
3   At an oil temperature of 110 ± 4 °C or 95 ± 4 °C, depending on thermostat installed, a distinctive increase of oil temperature on oil cooler should be noticeable (manually).
If not, replace thermostat (18-125). 18.8-120/1 F2