Wanting to find out on M103 where oil is leaking from. It's quite shiny on the front of the motor, but doesn't show any drips. I see drips on the hoses down below however. Before I start doing any repairs, I wanted to know exactly what all is leaking. I have heard of using die in the motor oil to check with an ultraviolet light. Wanted to ask if anyone is familiar with doing this, and how hard or effective it might be?

I wasn't sure if you can just use a ultra violet light like from a chain store or not. Seems I have heard you need to have UVL safety glasses on, as well. I pulled the belly pan tonight & cleaned everything very good. I ran it for 15 minutes, and I didn't detect any leaks. I didn't have the dye or light equipment yet. I left cardboard underneath it for a spot checker.

check you valve cover gasket.........

Wanted to report back on the leak detection. I changed oil filter etc. a few weeks back. Talked around a bit, and was told mainly just to do a spick & span clean up. This is what I did, and I left the skid cover off (for ease of checking). Well, I kind of felt lucky. No, leaks on the valve cover or the upper timing cover at all. The leak was from the coolant line going to the transmission & a bolt going in the the pan was loose leaking a bit. Got rid of the "If it's German it leaks for now." Kind of got spoiled by the 83 240D never a spot on the ground, but it's not a gasser!

Back to your UV light, I have a 12V incandescent lamp which works well but is hotter than Hades when in use. I just got a 9-LED UV lamp from Dicks for $10. It says "Scorpion Master" on it, I think, with a picture of a scorpion. Apparently, these are good for checking your sleeping bag too.

Definitely wear the glasses. Your eyes will become painful after a while without.