Hey gang,
Thanks again for your help and feedback when I was working on my fender. It was greatly appreciated. Recently I have run into a new, more significant, problem and I was hoping to know if any of you have experienced a similar problem and if so if you found a good solution.

Here is the deal:
I live in a town about 20 miles from the town I work in, my wife and I commute back and forth the 1983 300d. The town we live in is in a higher elevation than the one we work in, so the ride to work is all downhill and the ride home is uphill at a reasonably significant grade all the way.

Recently, the engine has started overheating (temperature gauge pegs all the way over into the red and you can smell the engine overheating in the cabin) when we come to the first stoplight or stop sign after coming up the hill. Once we can start moving again after the stop the temperature settles back down around the 100 mark, but those temps at a stop are making me very, very nervous.

It does not show this overheating problem after driving around town or while driving up or down the hill to work, only at a stop after the 20 miles uphill at 60 mph on the highway.

I took it to our local Mercedes specialist (who has the patience of a saint and is a miracle worker as far as keeping this car on the road. He has spent a *lot* of hours working with me on my old car and answering questions for me). He replaced the leaking coolant pump, flushed the radiator and did a full fluid change which the car was due for anyway. He also replaced the thermostat and temperature probe.

Unfortunately, this has not resolved the problem. The engine is still overheating after the drive uphill. Our mechanic has said that the next thing to do would be to replace the radiator. He also mentioned that we could try cleaning the system out with a citric acid flush but is concerned that doing so could damage the radiator or heater core. My problem is that I do not think that I can convince the wife to spend the cash it is going to take to replace the radiator right now.

Our mechanic has said that as a stopgap measure to try to keep temps down at a stop we could run the defroster at full blast to blow off some of the hot air.

Does anyone have any suggestions or has anyone run into a similar problem and resolved it in a successful and hopefully not too expensive manner?