SORRY for the delay. Culprit was a faulty valve cover itself. Had to bite the bullet and replace a oem one from ECS tuning. No more oil consumption (SO FAR) its been just couple hundred kms. Will keep posted.Any news?
I've just installed an OCC as well on a n52b30; the fittings were 6mm ID so really small although made by mishimoto. The fun part was it came with huge a 14mm ID cheap garden hose. Duh...
I've upgraded them to 10mm, I hope it's not going to cause too much pressure inside the crankcase, the oem ID is around 12mm. To fit the tubes to the oem hoses I use electrical shrinking tube, but it's something much thicker than normal.
The vent pipe gets oil on the inside walls so there is some oil flow through it and there is also some oil consumption.
There is also vacuum inside the crankcase at idle. I'll check the pcv valve for leaks tomorrow and also planning to add an extra pcv valve on the exit of the OCC.