[e90yyc]

I know this thread is a bit old but this seems like the most logical place to post this, so:

My car is 2007 with plastic VC. According to the PhaseP, there are two ways you can test your PCV system: with a hose on PCV diaphragm nipple, and another method that can only be done with the VC removed.

What is that second method?

I recently had my VC removed and tried blowing air through the system a couple ways. I was expecting I’d be able to perform a visual inspection of some sort, but I couldn’t see anything worth inspecting… The two breather orifices were intact.

Would appreciate any info in this regard. Once I know this I’ll share my findings. I’ve been experiencing what I believe might be high oil consumption, but I’m not positive. Hoping to rule out PCV.

Thanks!

[Prologic]

Originally Posted by e90yyc

I know this thread is a bit old but this seems like the most logical place to post this, so:

My car is 2007 with plastic VC. According to the PhaseP, there are two ways you can test your PCV system: with a hose on PCV diaphragm nipple, and another method that can only be done with the VC removed.

What is that second method?

I recently had my VC removed and tried blowing air through the system a couple ways. I was expecting I’d be able to perform a visual inspection of some sort, but I couldn’t see anything worth inspecting… The two breather orifices were intact.

Would appreciate any info in this regard. Once I know this I’ll share my findings. I’ve been experiencing what I believe might be high oil consumption, but I’m not positive. Hoping to rule out PCV.

Thanks!

Did you tried testing it by putting suction on PCV nippple? If it holds, then membrane is fine and there is nothing to worry about.

[e90yyc]

Originally Posted by Prologic

Did you tried testing it by putting suction on PCV nippple? If it holds, then membrane is fine and there is nothing to worry about.

This is where I was a bit confused.

The original post says to blow air in, rather than suck it out. When I performed this test, I was able to blow a small but steady stream of air into the nipple. When I tried to apply suction by drawing air out, I was able to suck for a very brief moment, but not any more than that.

Thoughts?

[Prologic]

Originally Posted by e90yyc

This is where I was a bit confused.

The original post says to blow air in, rather than suck it out. When I performed this test, I was able to blow a small but steady stream of air into the nipple. When I tried to apply suction by drawing air out, I was able to suck for a very brief moment, but not any more than that.

Thoughts?

This nipple is for membrane venting while it moves up or down. If in any scenario it does not hold low pressure or vaccum, it should have a small tear in it and needs to be replaced.

[PhaseP]

Originally Posted by e90yyc

This is where I was a bit confused.

The original post says to blow air in, rather than suck it out. When I performed this test, I was able to blow a small but steady stream of air into the nipple. When I tried to apply suction by drawing air out, I was able to suck for a very brief moment, but not any more than that.

Thoughts?

During suction the tear in the membrane may have sealed up due to upwards move.

I made a drawing of the chamber made up by the membrane and the upper section of the pcv where the nipple is located. The orange part is the diaphragm.

I recommend blowing on it to test, because in normal operation the ambient pressure which comes from the nipple will be higher than the other side of the membrane which is engine's crank case vacuum.
In normal operation the membrane will move down when there is engine vacuum, and when vacuum is gone it will move back to its rest. The spring under the membrane supports it and provides some balancing against engine vacuum pulling it down.

[PhaseP]

I recommend blowing on it to test, because in normal operation the ambient pressure which comes from the nipple will be higher than the other side of the membrane which is engine's crank case vacuum.

Correction on the above: The diaphragm (membrane) is pulled down at the lower center of it by intake vacuum, the remaining parts of the diaphragm at the lower section is subjected to crank case pressure, which would be positive (above ambient pressure) if it were not for the PCV functionality.

The chamber made up of the upper part of the diaphragm and the cap above it where that nipple is connected to is just a chamber of air. No air flows in it in normal operation with healthy PCV. The nipple is there to allow the diaphragm to move up and down easier. If nipple was closed, it would still move up and down, but against a small resistance made up by the enclosed air spring captured in that chamber. And at N51 SULEV cars, that nipple is connected to the intake via a small hose, which is to prevent venting crankcase gases to atmosphere even when the diaphragm is torn.

[PhaseP]

Originally Posted by Prologic

This nipple is for membrane venting while it moves up or down. If in any scenario it does not hold low pressure or vaccum, it should have a small tear in it and needs to be replaced.

+1 Since he could blow steady flow of air, it must have been torn.

[e90yyc]

PhaseP and Prologic: Thank you!!! Very much appreciate the drawing and great explanations.

Is it likely a tear this small could cause excessive oil consumption?

And finally, what is the second way to test the system that you mention requires the VC be off?

Thanks!

[PhaseP]

I don't know if it will cause excessive oil consumption. The least if diaphragm is torn, air will go into intake causing it engine to run lean and have not good idle.

If you were referring to me I don't know if I mentioned a 2nd way to test with VC off. You can try applying vacuum to the connection where the line goes to intake, but with VC off that will never seal.
The fact that you can blow into that nipple with steady stream of air indicates diaphragm is torn, there is no need for another test. It is supposed to be completely sealed chamber once the nipple is closed.

[Navigator_101]

PhaseP

Thank you SO much for making this!!
This makes it very clear and the way you took it apart, showed us; you should get a medal for it.

It is so good, do you mind if I show the pictures to my students? Just in the classroom, not all over the internet or anything like that. I want to tell more than just a simple pc valve as is in their books.

There is one thing that I do not get completely; this works on intake vacuum and that all seems very logical, but those engines have Valvetronic and therefore the vacuum is not much and always about the same? At least; that is my understanding of it.
When idle, it should suck the membrane to a close and when driving/throttle open, it should let the spring take over and there is suction > the blobby gasses go to the intake.
My understanding of the Valvetronic was: there is always the same low vacuum. In that case: there is something I just don't get?

By the way; I have the same car, has oil usage, took the outer Dish out and filled a teacup with the oil that came out......So I'm busy with the CCV replacement too
There is no vacuum hose on my car either but someone (I only have the car a few weeks now) closed the little vacuum connection with a small piece of hose and a screw in there.....
Hehe, now I know that is probably the culprit as the membrane can't really go down anymore! Had a very strong suction on my oil cap too.

Sorry for kicking up an older topic, but I really think it is fantastic what you did and I am very, very grateful!!

[Brian86]

N52 do indeed have a computer controlled butterfly throttle. It's primary job is to
*drumroll*
regulate the vacuum applied to the oil separator system.

Valvetronic drives the car. The throttle only chokes down a very small amount to get a few "hg in the crank case.

It's also a fail-safe mechanism to operate the car if the valvetronic actuators suffer a catastrophic failure.

If you're talking about the vacuum line to the top of the oil separator: some cars have one, some cars don't. It's just an atmospheric pressure reference. It doesn't really matter if it gets that reference from the air box or from an open hole.

[Navigator_101]

Thank you Brian86
Well, that explains it all; I clearly had my facts wrong.
My understanding was what I wrote and with that, I had read the butterfly was always fully open...... It's not the case I learn now and that seems way more logical.

The oil separator: if you have that line or not on your intake, the connection is there on the thing, right? For vacuum or for atmospheric pressure.
What I meant is that in my particular case, there is no vacuum hose, but the opening on the separator is fully closed off.....so it has no atmospheric reference either.
What I think that does, is the membrane is harder to close as the room above the membrane sucks its own vacuum.

Thanks again!

[Brian86]

somebody will correct me if I'm wrong, but I believe that nipple directly on top of the oil separator should be open to the atmosphere, either via a a vacuum line to the air box, or just left open under the hood.

That said n52 are extremely tolerant of CCV system malfunctions. The parts I removed from my car had failed in every way possible and until the check valve at the bottom of the drain tube got stuck open there was really no way to tell driving it.

I think the last one I bought has a 'vented cap' so debris doesn't readily fall into it.

[Navigator_101]

Yeah, I think you are right; you must be.
There is no use for that membrane if the top half is closed; it will not work.

Today I got the manifold off after a hard fight: the car has an LPG conversion and that was more than in the way.
What I saw was: the return pipe to the carter, the lower one, was halfway clogged.
That, and the pipe from the separator to the intake was broken and all wet outside, engine all wet of the oil too.
Together with the membrane not able to do its work, I make from all of this: (credits to the topicstarter and you for me now understanding the system!!)

- the suction on the membrane was to low, making it not close the middle pipe and therefore it kept sucking on the top pipe, from the valve cover.
- the closed of membrane movement, made this even more so.
- the clogged return pipe made the separation not all that good and oil came into the inlet manifold, together with "always suction" as described in former two points.
- there was "false air" as the inlet got always to much from two things: the not closed middle pipe in the separator and the pipe from the sep. to the inlet leaked air in.
- because the separator was always open; there was to much suction in the carter: I felt that on the oil cap.

When I get the manifold off and turned it over: a proper coffeecup with oil came out! Maybe even a quarter to half of a liter!

I forgot to check the "ball" closing in the return pipe by the way; I'll check that one tomorrow. Now I'm curious

My car had the issue of -when getting up to temperature- not having proper power. Especially sometimes it just "hung" at 1500 rpm and only accelerated further when I floored the gaspedal. It has low power anyway and from time to time I got the engine light on, saying the mixture was lean.
I'm really hoping my repair is going to fix that, but after reading your post.....I'm not so sure anymore.......
Well, I have to change it out anyway and I'll just have to see.

Sorry for the long story: I just had to "tell someone" and my wife was less than interested

[PhaseP]

Originally Posted by Navigator_101

It is so good, do you mind if I show the pictures to my students?

I don't mind at all.

[PhaseP]

Originally Posted by Navigator_101

PhaseP
There is one thing that I do not get completely; this works on intake vacuum and that all seems very logical, but those engines have Valvetronic and therefore the vacuum is not much and always about the same? At least; that is my understanding of it.

As Brian86 already mentioned, there is still a throttle on these engines. My understanding it is there as a fail safe if valvetronic malfunctions, and also to cause vacuum as computer decides. I don't know any details on when and how computer decides to use the throttle to cause vacuum, but it does. All those stories and videos about whistling engine on idle because of air getting sucked in from crankshaft seals and very hard to open oil plugs indicate at idle throttle is in use (and a stuck open PCV).

Another thing, even if there is no vacuum on the intake side, there will be positive pressure on the crankcase. And if it was not vented somewhere, it would increase as engine burns gas. The "Positive" part of the PCV acronym. It would go into intake with the intake ventilation PCV provides, even without intake vacuum.

[Navigator_101]

Thank you PhaseP!
Very nice of you.
Thanks for the explanation too, I appreciate that.

[Navigator_101]

Is anyone familiar with this?
The pipe from the separator to the inlet manifold, is one straight pipe on my car.
In the new set I ordered, they gave me some kind of T-pipe, with 1 connection extra.
Also, the pipe is about two inches to long.

So, I called up the official dealer, they gave me the same pipe!
The old one is not there anymore, he couldn't order it from BMW either.

I can't do anything with this pipe, I need the one I had......
Is there some kind of modification or something, does anyone know?

[PhaseP]

Early N52 manifolds had one connection point from CCV. Later changed to two connection points and so that Y shaped hose.

Yours must be an early build.
Yours is probably this part number 11617522933 https://www.ecstuning.com/b-genuine-...e/11617522933/

Later ones are 11617559530 https://www.ecstuning.com/b-rein-par...617559530~ren/


From Realoem.com site, E60 models and dates using 11617522933, the single output vent hose:

https://www.realoem.com/bmw/enUS/par...933&series=E60

They sell it on ebay Netherlands, if you search with that part number.

[Navigator_101]

Thank you PhaseP!
Found it and ordered it
Weird that the dealer just don't sell them anymore; those cars are still out on the road.
Thanks again mate!