If you search the archive under the topic "Replacing coolant for 94' C280", you will find the suggestions that Benzmac gave for purge the system. He says:
Be sure the engine is cold before attempting the change. Big note...When installing new coolant be sure to try to overfill the reservoir this is the only way to purge the coolant system. After the system is completely full, turn on the defrost and crank the engine. If you don't get heat out the top soon, turn the engine off and add more coolant.(Until it pours out the top of the reservoir)
Does the gurgling sound happen only when the heater is on or it doesn't matter? I can only hear the gurgling sound when I have heater on with my car. Any suggestions? Should I add more coolent to the reservior? The water temp is steady at about 84 C. It goes to 92-94 C in traffic jam. It once went to 100 C mark when climbing a steep hill with 2nd gear.
Harry (94 C280)