Haven't had my hands on a 94-95 W124, but on other cars this usually means a slow leak somewhere. Can be water pump leaking out the weep holes (and the coolant drops on the ground off the front of the pan) or any other hose in there.
Best way to find it is a pressure tester.
The worst possibility is a cracked head, not usually a problem on the M104.
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!