I've been keeping an eye on a little oil leak since having a new valve cover installed nearly a year ago..
I narrowed it down to the valvetronic area, the void between sparks 3 and 4 was filling up with oil from what I suspected was the gasket.
If I left the oil to build up (over 100miles), it would overflow during hard left hand bends and drip onto the hot exhaust, yuk..
So every 50miles or so I'd pipette the oil out from the void and I just lived with it. Until last week.
I got the Valvetronic out to inspect the gasket. The gasket was fine but look at the Valvetronic face that mounts up to the gasket, it's bent up on the RH side. I suspect the BMW specialist who installed the new valve cover either dropped the Valvetronic motor at some point. Or maybe screwed the Valvetronic to the head before winding the splined gear into position. Who knows.
Before (notice the bent up plate?) and after some gentle persuasion:
You can see where the oil was collecting under the Valvetronic:
I put a new gasket in anyway, added some more 'bite' to the gasket screws with some chopped up plastic zip ties (the valve cover is made from cheese it seems and the previous gasket installer (the same BMW specialist) must have torqued them a little too much, they were OK, but not great.. Much better now) and I re-installed the motor with new bolts following the guidance to screw the splined gear in the correct direction when removing/installing.
Ignition on for 30s, off and on again for 30s.
It started fine with zero lumpy timings. Nice.
Its been 50miles with no new oil appearing. Problem solved.
I still dont know if it was the gasket, the bent Valvetronic motor plate, or the less than perfect gasket threads.
I'll give it another 50 miles and if it's still dry, the engine cover can finally be installed for good. (it's been kicking around my office for months)