I would recommend doing a coolant flush and change the percentage of coolant used. Here is what I found works really well with my car and keeps it under 98C even in stop and go traffic.
Add 38% MB Coolant, A bottle of Redline Water Wetter (Pep Boys has it), and the remainder water. Water wetter allows you to use less antifreeze which will keep your car running cooler.
Hope this helps.
02 C32 AMG
84 190E 2.3 5 Spd