2003 GTI LE RFI Oil System Question

[Trueoo7]

Can some one explain how the system works on this model? I've read through the shop manual but I'm not sure if its a positive pressure type system or a pump. On the oil injection system for this ski there is a hose on top of the reservoir that goes to the bottom of the engine on the spark plug side. It is half filled with what I presume is oil. Is this line supposed to be free from liquid to supply air pressure to the tank? I'm getting a low oil warning and the tank looks a little below half full. I was trying to use up as much oil as possible before I added a different brand so as not to mix oils.
Thanks

 

[wfo speedracer]

It is an actual pump, the bigger lines go to the rotary valve cavity , it is fed by gravity and the rotary valve gear spinning slowly moves oil through the cavity, the smaller line with the oil filter in it goes to the oil pump. It is gravity fed to the pump, the pump pumps the oil through the small oil feed lines to the engine, it does not and cannot pump oil out of the tank to the pump !

 

[Trueoo7]

Yes those lines come off the bottom of the tank and go to the intake side of engine but there is one off the top that goes to the spark plug / fuel rail side that I can't figure out. Do you know if it should be half way filled up with oil. Also if I change the oil filter out do I have to re-prime the pump?
Thanks for taking the time to answer.

 

[wfo speedracer]

That is the return for the rotary valve cavity, whatever is in it is whats in it.