I went through all of this and replaced everything (raditor, temp sensor, water pump, fan clutch) and still the temp would go up over 100c. Than I ran into a mb tech on the golf course and he had me check the wiring from temp sensor to the cluster. I soldered a new end on the temp sensor AND ran a new ground from the cluster (back of temp guage) to the body. Now the car runs at constant 90 t 95c and I live in south florida. The ground was the last thing that I did and that solved the problem.