Look in the area of the motor mounts. On the M117, the left drain is just forward of the mount and the right drain is just behind the mount, I imagine M119's are probably similar. Laying on your back look upward and on a flat at the lower edge of the block you should see a 19mm bolt, that should be the drain. On mine, once I pull the plug nothing came out, there was an inner plug of crud and buildup which had to be poked out with a screwdriver.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.