Why is my car STILL running so hot?

[Ben300SD]

I think I am going to go crazy. My 300D had been running much hotter than I would have preferred, as the radiator was plugged. I was going to flush it, but one day last week it just decided to start leaking. I freaked out and had it replaced, as I did not have time to do it myself. I had been planning on replacing it myself, and I had even found a radiator for about $300, but I just couldn't wait for my car and I didn't have time to do the work.

Anyways, now I am $600 poorer, and although my car cools off much quicker than it used to, it still heats up when I don't think it should. The problem may be that I am not sure how my car should behave, but I have not driven another W124 that behaves quite like mine.

When I drive at or below 60 F (outside temp), the engine temp will hover around 85-90 C. When the outside temp is 73 F or greater the engine temp is at least 85 C, but often as high as 95 C. Here is the problem. Whenever I put any sort of demand on the engine, like driving up even a very moderate hill with the A/C on, the temp will often rise to 95 or 100 C. Today it managed to climb to just above 100 C while I was accelerating onto the highway, with the A/C turned off!! The outside temperature was only 76 F.

What do I need to do? I don't have money to keep throwing at the car, but I am willing to spend what it takes to get it to run properly. This is seriously causing me a great deal of stress. I commute at least 90 miles per day, and every one of those miles is spent worrying about not overheating my car. Any suggestions?