The early W210 diesels (96-97) experienced some problems with the engine surging unexpectedly. The addition of the turbo in 1998 seemed to solve this problem. The W210 is a great car and I've had no problems with mine at 38K miles. It's not the best on mileage however. According to posts I've seem on this board, the circa 1990 E class 2.5 turbodiesels get better mileage.

Use the search function for "engine surging" and see what comes up.

__________________
99 E300 133K
98 ML320 99K
87 Saab 900 Turbo Conv 123K