Well this thread is quiet for some time now, but the problem still exists with 4.8is in 2016. I have the same problem with my 2004 (a bit of smoke after 5-10 min idle) and i have been reading for hours these 27 pages and external links and info. After reading all that i am also suspicious if i have a valve stem seals problem or a vacuum leak. People are saying if i check my plugs i can see if i have a vacuum problem (if all of them are the same) or seals are bad (several plugs darker than the others).
BUT i was thinking i will:
1 - disconnect 2 hoses going from valve covers to inlet (one per bank)
2 - plug hoses so there is no vacuum leak in my inlet
3 - leave open those two holes on valve covers so gases can freely go into atmosphere (maybe i will put some hose just not to have oil sprayed all around)
Ok i know membranes in CCV will not work properly (no intake vacuum) and will be always open and oily gases are going to pollute, but i am doing this just temporarily to eliminate ANY crankcase gases getting into intake. So i am hoping to see changes... so if my "idle smoke" is gone than it is a vacuum problem and if it is still there than it has to be valve stem seals.
AND FINALLY my question is: is my logic correct and can i do any harm to the engine if there is atmospheric pressure in my crank case (instead of minus 22-50mb) since CCV is always open because there is no vacuum from my intake to pull them down against the spring?
Any info/suggestion/opinion is welcome!
here a video of my cloud after 10 minutes on idle:
https://www.youtube.com/watch?v=K41f7TICpc0