Need some advice to troubleshoot oil on sparkplugs and boots. Searched the net and xoutpost for a while but didn't find a lot.

A couple years ago I had burning smell from oil dripping on exhaust manifold. I replaced the VCG (including the rubber strip for the sparkplugs) and rubber under the washers.
That problem disappeared. Since then I haven't driven car much at all.

Today I was replacing spark plugs and boots and noticed that when I took the boots and spark plugs out, they were dripping with oil.



So from the research I did so far, there are a few possibilitilities:

- Warped valve cover. I'm not sure how to confirm for sure. There are not leaks on the outside. Only inside the tube. Not sure if the cover can be warped only where spark plug tube are? How can I even tell?

- Bad install? I'm not sure if I could've screwed something up, but it's not complicated pressing the string of spark plug gasket into the cover when changing VCG. Why would it not make a good contact?

- Spark plug tubes. Quick search shows parts for spark plug tube, but these seem to only be applicable for 8 cylinder engines. Doesn't look like i6 has replaceable tubes.

- CCV system. I plugged the extra hole on dipstick and installed a catch can.
https://xoutpost.com/bmw-sav-forums/...roject-12.html
I don’t know if catchcan can be causing issues but I didn't think so.

I'm thinking of replacing VCG again but I'm afraid it won't fix the issue. I'm thinking about maybe buying a new (used) valve cover as well.

It's quite disheartening to see so much oil on the sparkplugs. Oil is not contaminated with coolant, so I guess headgasket can be ruled out as the cause.