Your water pump is shot, it's leaking out the bottom weep hole, but the coolant runs down the body of the pump, down the block to the oil pan, and down the oil pan a couple bolts and then onto the ground.
Just replaced the water pump on the TE a couple weeks ago, slow coolant leak.
The occasional oil droplets can be from oil left in the cooling system from previous problems -- if you don't use something serious to get it out, it hangs around forever.
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!