DIY Solution to M54-M52TU CCV problems

[cn90]

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:

[imalabil]

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.

[axgordon]

Originally Posted by imalabil

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.

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.

[cn90]

Originally Posted by axgordon

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.

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.

[imalabil]

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 Bobby]

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?

[Ricky Bobby]

axgordon, interested now to hear about the shop owner's opinion on the piston rings. He believed that replacing piston rings on stock CCV setup on M54 would solve oil consumption in higher mileage vehicles? Or alternatively you could keep the low tension piston rings and do the "CCV Bypass/PCV install" like you have done and solve the same issue?

You are correct I just rolled 80k miles a week ago so I'm not as "up there" yet.

[cn90]

trader4,

I am talking about brand-new stock system from showroom. From an engineering standpoint, E23 is more simple than M52/M54 setup.

1. In the E23, the mixture of oil and vapor goes up the slope (the simple tube). Vapor keeps going up while oil, being heavier, drips back down the valve cover area.

2. In the E53 M54 setup, the Intake Manifold sits LOWER than the valve cover.
So the mixture of oil + vapor goes DOWN the slope and pools at the Separator area.
In theory, oil being heavier goes down the dipstick housing and vapor gets sucked into the Intake manifold.
However, when the membrane opens up (under certain vacuum condition), some oil gets sucked into the I.M.

[cn90]

Originally Posted by trader4

... your PCV design...

@trader4,

It is not "my PCV" design, it is BMW engineer's design. I have nothing to do with the design.

The X5 M54 CCV setup is dumb. This is because the Intake Manifold sits BELOW the valve cover. In the process of routing oil + vapor mixture, BMW likes it or not, the mixture settles at the Separator.
BMW engineers hope that oil being heavier runs down the other hose to the dipstick tube, while vapor is sucked into the I.M.

Nice thinking but in reality, some oil is sucked in the I.M.

The E53 M54 CCV setup is dumb from day 1. Too complex for a simple CCV issue.
In Honda car, is is a simple valve.
In the E23 from 1980s, it is a simple hose, as conceptually illustrated in the mod in this thread.

Again, it is NOT my design, it is dumb BMW design. Engineers sometimes go forward, and sometimes they go backward. The M54 CCV is an example of backward thinking.

[cn90]

Originally Posted by trader4

...You make it sound like the
oil separator just relies on gravity to separate out the oil...

trader4,

I don't make it sound like anything. I don't want to argue with you how the CCV works, you may want to do more reading on the engineering aspect of it.

Most of the oil will go down by gravity, a little bit of oil will stay around at the Separator. When the diaphragm opens, vapor will be sucked in and some oil will be too.

The analogy is: when you open a door to a building and some unauthorized person sneaks in at the same time.