I have a problem with the coolant temperature in my W111 Coupé, M127. For the first 50 km, everything is fine; the needle is exactly at 80 degrees. After that, however, it slowly drops, and after another 50 km, it sits below the 80 degree mark and the next. Back at the workshop, I read about 65-70 degrees with my infrared temperature gauge on the ESP water distributor.
Everywhere else, I read around 80 degrees.
The thermostat reads 87 degrees, and I've tried two new ones, with the same result.
Does anyone have any advice?
