Nice post Corey. Not to disagree , I do have a question :This is my first post, I just wanted to clarify the operation of the ccv valve
The amount of air is often dependent on intake manifold vacuum. The ccv on the other hand is designed to ONLY open when there is an ABSENCE of vacuum in the crankcase. The diaphram in the ccv will be fully open upon startup for a brief second until engine vacuum accumulates in the crankcase, at which point the valve will then close.
Are you trying to say that Is designed to be always open and close when the flow is big through it? If yes , sorry for question. If not, I'm all ears...
If you take the positive crankcase ventilation valve and suck air through the hole where the intake pipe is connecting you will see that you can always suck the air. But if you change the speed of the air absorbed the diaphragm will close . This makes me believe that air is going through the diaphragm at all the times and it is open but is closing when the pressure on it is greater. For instance is open when the engine is idling or the rpm increase until a certain point and under a sudden acceleration is closing. So with another words it does not allow more air than needed to be absorbed by the intake vacuum.
I might got this wrong , and if I did please make some light on it.
This is a Quote from alldata :
The Positive Crankcase Ventilation Valve (PCV) system directs crankcase "blowby" to the intake system in order to prevent vapors from escaping to the atmosphere.
How it runs:
The blow-by gasses which are produced during engine operation collect in the crankcase.
The crankcase is ventilated by a pressure controlled system. The oil vapors in the crankcase enter a cyclone-type liquid/vapor separator (OSV-behind the timing chain) which allows the liquid oil to return to the oil pan and the oil vapors to be drawn into the intake manifold via a pressure control valve.
The pressure control valve is centrally located in the rear end cover of the intake manifold and is connected directly to the cyclone-type separator via aluminum pipe. It varies the pressure in the crankcase continuously depending on engine load and speed conditions. This prevents blue exhaust smoke and excessive oil consumption on deceleration due to peaking manifold vacuum, and assures reliable crankcase venting during all other engine operating conditions.
So knowing this, is the PCV always open and close under big pressure conditions?
UPDATE: This is a must read for those looking for more information : http://www.bimmerfest.com/forums/showthread.php?t=534005