Take a look at the W124 Forum
Several of us E300 and E320 users have had similar issues. There is lots of info on the W124 forum about changing the thermostat, adding resistors to the aux fan curcuit and a good debate about the pro's and con's of runing hot.
Bottom line appears to be you can make it run cooler but actually 110 degrees is OK and better for the engine than running too cool.
My 1991 UK Spec 300TE-24v runs up to 110 if I sit in traffic for more than 5 mins. The aux fans then kick in and bring it down to 90, a few mins more they cut out and it rises to 110. They cut in again and so on......... like a yo-yo.
Andy
Several of us E300 and E320 users have had similar issues. There is lots of info on the W124 forum about changing the thermostat, adding resistors to the aux fan curcuit and a good debate about the pro's and con's of runing hot.
Bottom line appears to be you can make it run cooler but actually 110 degrees is OK and better for the engine than running too cool.
My 1991 UK Spec 300TE-24v runs up to 110 if I sit in traffic for more than 5 mins. The aux fans then kick in and bring it down to 90, a few mins more they cut out and it rises to 110. They cut in again and so on......... like a yo-yo.
Andy
