Continuation of Part II...
As I wrote above, the first generation of fuel injection systems in which the blow-by gas raised before the throttle of the ball is far from perfect. Why? YES, just because, and throttle and sensors of the flowmeter and the temperature of the air is constantly polluted, they formed soot, oil film, etc. after a certain interval all this led to unstable operation of the engine, they had to be constantly cleaned.
The next generation of this system has a lot of bugs fixed:
First, now the gases are summed after the throttle. Which reduces pollution, as the throttle and sensors.
Secondly, the vacuum of the intake manifold is offset by the EGR valve blow-by gas.
As for the second item, a little explain. If the channel from the crankcase, would be directly connected to the intake channel, all the exhaust gases would just suck in the intake (because the vacuum on the intake is huge). Also would Carter has created pretty a negative pressure, which is bad for all sealing elements, such as seals and gaskets (e.g. crankshaft)
What valve prevents all of this. A little about the device.
The valve has two chambers — low and high pressure. Using both cameras is stock, which is attached to the membrane, on the other hand locks the low-pressure chamber.
The high-pressure chamber directly connected with the crankcase (there is one channel). When the blow-by gases start to increase the pressure, then the membrane unfolds and opens the low-pressure chamber (the second channel), in fact, offer a direct access to the intake manifold, which sucks the whole "working out" of the crankcase.
Once the pressure is gone, fell into the high pressure chamber, then the membrane returns to its place, closing the low-pressure chamber.
Thus, constantly maintained the desired pressure in the crankcase (just below 1 ATM), intake manifold, etc.
This site maybe we have a lot to say in particular about the failure of the engine or the EGR valve. The topic is vast, so I shall mention only a few important points.
When a faulty valve:
When his "go crazy", and it is always open – that is, the exhaust manifold pulls gases from the crankcase (vacuum appears). You will have a constant lean mixture, there may be errors , Check Engine, the machine will not work consistently (swimming speed, fall, pull). If you try to Unscrew the head cover block on a running engine to remove it will be difficult, it seems to be something to tighten
When his "go crazy", and it's always closed – then working out will not go away in the intake will create positive pressure. Likely to dislodge oil dipstick, battery cover, head block and throw oil.
When a faulty engine:
The main reason here, one is wear of the piston, for example rings, the walls of the cylinder block.
When running the engine, if you Unscrew the cap of the cylinder, the gases will simply escape from the filler neck. The cover will simply knock can also spill oil, and liberally drops, and go bluish color smoke.