^axgordon, please share pics of your setup and parts needed to make it look cleaner and completely "plug and play"!

How was vaccuum since converting to the simple PCV system?

At one time we had three BMW vehicles with the M54 engine. All were driven by the same drivers, on the same roads, in the same ambient temperatures. All were purchased new and broken in the same way. All used the same oil. The E53 consistently used more oil, over several years of concurrent comparison. The only difference was that it was a heavier vehicle. The engine was working harder. (Which incidentally meant that it warmed up faster). In terms of oil consumption, I don't think CCV design had anything to do with it.

In mulling this over I have a couple of questions before I take the plunge this weekend:

1. Oil will reduce the octane value of gasoline. This change will presumably put more oil vapor into the intake manifold. Has anyone noticed a tendency to ping/knock with this set-up?
2. I'm wondering if more oil combusted could foul 02 sensors or catalytic converters.

Of course, other cars use simple PVC systems and don't necessarily suffer these side-effects, but I thought I'd ask.

Also, I changed the oil filter housing gasket shortly after I got the vehicle in 2010. At that time there was no burned oil smell, just a lot of leaking at the plate access hole for the oil drain plug. Yes, it could be leaking again!

Ricky,
See attached pictures. I did not measure vacuum after the mod yet. The crankcase remains under vacuum for some time after the engine shut off - i don't see any issues with that.

Imalabil - I do not have clear answer why this mod greatly reduce oil consumption, however this is what many including my self observed. This is clear indication that less oil got burned causing less impact on the fuel octane and less stress for catalytic converters and O2 sensors. My experience based on less than 2500 miles. I will continue to monitor and report to the board.

axgordon, thanks for the pics, they look great. Since that PCV needs to be vertical, call me stupid but could you not put it vertical facing downward and use a 90 degree elbow with hose to eliminate the "hose loop" on the upward facing PCV?

This happens because of the loop of the hose going UPWARD: oil goes down by gravity (not by separation as in the E53 stock CCV valve), and air gets sucked into the loop. So oil consumption is minimal.

Conceptually, this is similar to E23 (1983-1987 735i) with simply a hose slating upward as the CCV, talking about simplicity.

Two things come to mind...

1. For those who want to sell the car in the future, the next owner will likely has some questions for all these "snakes" running around on top of the engine. You will need to explain it to him/her.

2. The E23 (1983-1987 735i) Intake Manifold sits ABOVE the engine.
So the CCV system in that car is simply a tube going upward, see photo for #11 in E23: