Small hole in bottom of engine ???
 

I was changing the transmission oil on my ec 300 2006 and i notice a small hole with out any srew on the botton of the engine . This is not the allen bolts for the crankcase . I am talking about the one in the picture with the arrow ? I am suppose to have a srew in this hole ?

Thank you for the help

Stephane

Some say it is used as a hole to mount a jig when the cases are built. May be true, I don't know. It also is drilled upwards at an angle into the ignition/flywheel housing and acts as a drain for errant moisture. They aren't meant to be plugged.