Oil Leak From Back of Engine - 06 Jetta

This is all in regards to a 2006 Jetta Sedan TDI, 5 speed manual.
I've got an oil leak somewhere on the back of my engine, but I can't tell exactly where it's coming from. The back of the engine block was completely coated with oil, all the way from the oil pan, up to as high as I could see from below. There was also a significant amount of splatter on nearby hoses. The lower hoses had a better coating than higher up hoses.
I did an oil change on Wednesday in the evening, and now 1 day later there doesn't appear to have been any significant oil loss.
I've wiped everything down and will try to take another look on Friday to see if I can tell where the oil is coming from.
Does anyone have any ideas what might be leaking, or what I should look for?

You had the vlave cover off to check the lifters? if so this is probably leaking...If not then it could beloose as the engine vibrations loosen the VC screws..

I haven't personally had the valve cover off. Had the timing belt done 17K ago, but I didn't do it. I'll check the cover bolts tonight and see if that fixes the problem. Thanks.

The valve cover fasteners loosen over time and the back side of the BRM engine get's an oil bath if not attended. Happened to our MY06.5 TDI (BRM 1.9)
Additionally the air intake plumbing at the turbo has an interior placed o-ring which can allow oil to seep; this often shows itself as oil dripping on the H20 hose's beneath or nearby.

Try a little torque on those valve cover fasteners; think its a torx size 25 ???