I am not here to prove anything. I asked about the vacuum because I was not getting any @ the oil cap. After taking of the plenum & making sense of this engines design I discovered that there will be no engine vacuum under the oil cap(I did not know this a few days ago & like I said nobody had an answer). What bothers me is that you confidently said that the vacuum will be present in that area & that I will create a HUGE vacuum leak if I remove the oil cap. You should not answer questions about things that you are not 100% sure about,or you should say that you are not sure. Also the vacuum on this engine & any other engine will be present when the engine is running only after throttle body(between throttle body & head,not throttle body & air filter). Air only fllows in that area towards the intake/throttle body. Plenum will have vacum if it is located between the throttle body & head(any regular BMW engine,or any other make). One thing you are right about,one or more seals will get blown if the crankcase is not being vented(bad PCV can be enough for that to happen). So do you agree that there will be no vacumm in the valve cover area due to "pressure" caused by pistons travel up/down?There will be no pressure in the crankcase due to breather tubes. Because the crank is getting vented in the plenum/oil separator, which is part of the plenum & it is hollow inside like a pop can (it does not work like a PCV valve)...but you probably knew that..You may say that I have a funny way of wording things but if you were not acting smart & being sarcastic you would not answer my question the way you did. That made me change the way I am talking to you. I did not start this conversation in this tone,You did! By the way, if I did word my post in a funny way,I apologize because english is my second language. Take care.
P.S. I would like to know if you agree with me on this subject (S38 vacuum)