The PCV valve opens at max vacuum which pushes the pintle up into the valve body which reduces flow so max open is actually min flow and min open is max flow.
You don't want it closed while the engine is idling and even with the PCV on it's lowest setting it still pulls oil. And when flooring it it is pulling a lot of oil. I pulled more than a quart and a half in less than 100 miles. The problem is the IE valve cover. Because the valve cover is so low in volume the baffle has to be near the breather opening which causes a lot of oil to get sucked out under vacuum. There's no way to fix that so I'm just gonna go back to venting the valve cover to the air intake and slap a filter on the oil filter breather tube. I'll still lose about 2 quarts in between oil changes but it will mainly end up in the catch can. It's like a continuous oil change. I have just been adding 1/2 a Quart every 1000 miles. I could put the stock cover back on but I'll still be losing some oil so might as well keep the bling.
It's just a question of perspective, but the valve close at max vacuum, we cleary see it on the above picture, the valve seats (close) on high vacuum, when a valve close it's to stop the flow just like any other kind of valve.
It still strange that you are losing that much oil. Here are some explanations for the people who wonder why since it's a forum and I know some might be interested in reading it.
First, we know that pressure travel from higher one to lower pressure (this is what we can call a flow). The PCV system is here to avoid building excessive pressure in the crankcase by venting the crankcase air to a lower pressure in order to decrease the pressure in the crankcase. For emissions reasons, manufacturers vent it to the intake manifold to burn oil vapor and other contaminants. On our car, we don't have a classic PCV valve but a PCV diaphragm style which the opening and the closing of the diaphragm is calibrated by a spring which apply tension to the diaphragm to keep it normally open. There is also a tiny hole on the PCV which is the atmospheric pressure (~14.7psi). The rubber diaphragm isolate the "atmospheric pressure" from the "intake manifold pressure".
At idling / crusing we have a vaccum peak, a vaccum is the negative difference of pressure compared to the atmospheric pressure, for example a vacuum of 4.7psi would mean the pressure is 10psi, so anything at atmospheric pressure would move to that vacuum, the bigger the difference is, the bigger the flow is. Where am I going with this ? When the PCV diaphragm or valve is open (the spring isn't compressed), the crankcase is linked to the intake manifold, so if there is vacuum in the intake manifold, there will be a flow (ventilation of the crankcase). But we don't necessarily want a lot of vaccum and ventilation all the time, this is why the PCV is calibrated with a spring, it compress under a certain vacuum. When the intake manifold reach the certain vacuum, it closes the PCV and the spring is fully compressed. In this case, the crankcase is linked to the atmospheric pressure (by the tiny hole on the PCV), this means that it won't vent until the crankcase pressure is over atmospheric pressure (~14.7psi), the flow rate will also be lower than when there is vacuum because the difference of pressure will be much lower. For example, if the crankcase pressure is 20psi, we have ~5psi of difference with atmospheric pressure, the difference is much bigger if we compare 20psi to a vacuum (which is already lower than atmospheric)
I don't want to make it sounds complex to you, the PCV isn't an ON/OFF valve, it's modulated by the intake manifold vacuum and the spring calibration. You now understand why when the PCV diaphragm fails, you have a bad idle since the atmospheric pressure goes from the tiny hole on the PCV to the intake manifold just like if you would press on the throttle, our MAP based cars inject fuel based on bad data's, reeving the engine, but the ECU try to correct the idle and it does a loop which lead to the unstable idle.
We also know there is a "breather" that bring fresh air to the crankcase for ventilation, this air comes from the intake piping which is atmospheric pressure, the PCV opens and closes to keep a certain pressure on the crankcase. The excessive pressure that build up in the crankcase comes from the cylinders due to some vapor that goes through the piston ring. The role of the PCV is not only to avoid excessive pressure but to vent the vapor that contains contaminants, humidity, etc, as I told you, the breather bring atmospheric pressure so there will always be some venting. If you are loosing oil through the PCV, it means there is too much vacuum / ventilation or your piston rings are less effective. Keep in mind, that VW took time to tune the PCV, if you plan on using an aftermarket valve cover do not vent it to the intake manifold except if you have a aftermarket PCV that is properly tuned. If you are venting to atmosphere and you are loosing abnormal quantity of oil, it might indicate bad piston rings or you got a small leak somewhere else. Even if the IE valve cover is less thick and doesn't have a baffle, I don't believe it would have a huge different in velocity compared to the OEM system, it's gas not fluid, the baffle isn't that restrictive
I know some of you might have heard that bad PCV on the 2.0 TSI lead to oil consumption but it's different from our 2.5L, they used thinner piston ring and honed the cylinders in "crossed pattern almost vertical" to decrease friction and increase economy, the way it's designed make it easier for the "oil" to slip through the rings, so when the PCV isn't well calibrated on those engine, there is enough vacuum to suction a lot of "oil". It's been fixed near the 2013.5 Gen (thicker piston rings and cylinders honed horizontally)
Hope you enjoy the reading
I'm not a huge fan of lightweight pulley since you don't have any kind of harmonic balancer, I would recommend a RS3 / TT-RS pulley instead, but it's not free