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Crankcase Ventilation Valve

On the VANOS repair site (Rajaie) posted this trick

"The crankcase vent valve and 4 associate hoses fail and cause a vacuum leak. The valve gets stuck open and the hoses crack. These last 70-120k miles and usually fail 80-90k miles. Here are a couple diagnoses.
At warm idle, place a small plastic freezer storage bag on its side over the oil fill hole. If the bag sits on top or gets slightly sucked in, ~1", the valve is good. If the bag gets significantly sucked in the hole the valve is stuck open and bad.
With the engine off and cold, carefully remove the hose at the valve cover front corner. Blow hard into the hole. You should hear oil bubbling in the oil pan. If you don't hear the bubbling the top or bottom hose is likely cracked. The bottom hose often breaks just below the valve connection. There can also be cracks in the other two hoses."
Good to know.
 

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I received a PM asking for help with "distribution piece" noted in post 23. I couldn't attach an image in my reply PM. So here it is.

I pinched this image from another post & marked it up with the red text. The yellow text appeared in the original and isn't relevant in this instance.

 

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That was me! Thanks to RDL for a fast, cordial, helpful response! Seems obvious now, but I was not sure! Great forum!

As I told him...

"Great. That's perfect! Seems like a "duh" moment now. I was just looking at that piece a couple days ago as I was picking individual pieces of dog food out from under my fuel rail with a retriever "pick up" tool... Dern mice!

Thanks a bunch for the speed and courtesy! I have to admit reading some things on a CCV delete and an oil catch can are making me ambivalent about which direction to head! I need to do more research on those alternatives.

Best wishes!"

...unless you guys want to tell me why the delete is a bad idea!? Heh...

Cheers!
 

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Poolman,

Dipstick housing represents crankcase prssure, so it is almost always high from blow-by combustion. The dipstick can never suck in.

Vacuum exist in the Intake Manifold only.
Wrong... Pull your dipstick with the engine running. There is vacuum. Pressure would cause the dipstick to shoot out.

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Discussion Starter · #69 ·
Wrong... Pull your dipstick with the engine running. There is vacuum. Pressure would cause the dipstick to shoot out.

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In the world of Physics, a pressure in a chamber can be positive or negative. When it is negative (against ambient atm), it is referred to as "vacuum".

So the word pressure is a generic word in the Physics world.

Normal: slight vacuum.
Blocked CCV: pressure builds up and can blow the dipstick or RMS.

This is why I posted that sentence in this thread, which talks about blocked CCV.
 

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Blowby combustion in the crankcase = positive pressure

Vacuum is negative pressure, which you claim is only present in the intake manifold. Which is incorrect. Its present in the entire crankcase.

Sent from my LG-G6 using Tapatalk
 

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Vacuum would only be present in the dipstick if the PCV/CCV system was working correctly. If a PCV port on the valve cover were disconnected (say on an engine with a traditional PCV setup) from the intake manifold and capped off then the engine would be creating positive pressure. The PCV relieves crankcase pressure with a controlled vacuum leak via the PCV system.

My old Volvo 240 kept blowing the dipstick out of the tube because the oil separator box was clogged and did not allow any pressure to be released into the intake. Volvo has their own version of a PCV setup as well but its the same principle.
 

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What if the O-ring is bad on the oil dipstick what is still make the glove blow up

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My guess is that it would not and oil would be leaking out the dipstick tube mount point, but if you have over a 100,000 miles on your BMW engine, it's recommended to change your CCV and hose's, so you should consider doing it.
 

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What if the O-ring is bad on the oil dipstick what is still make the glove blow up

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Assuming everything else is working properly, a bad O-ring would leak air into the crankcase since the CCV maintains a vacuum of 4-6 inch water column. The engine would see this as a vacuum leak, just like any other.

Or are you asking if both the CCV and the O-ring are bad?
If the CCV failure mode is to create pressure rather than vacuum (i.e. blow up the glove) then air would leak out at the faulty O-ring and could carry oil droplets with it, making a mess around the tube.
 

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Discussion Starter · #78 ·
Well,

When a PCV system fails, usually it is from a clog ---> increased crankcase pressure ---> oil leak past the seal etc.

The video you posted above is from a different mode of failure: too much suction. Funny enough, this is exactly what you want in an M54 engine to reduce oil consumption.
The "BavarianE39 mod" is exactly that: creating a lot of suction to reduce oil loss from leaky piston rings.
 

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Well,

When a PCV system fails, usually it is from a clog ---> increased crankcase pressure ---> oil leak past the seal etc.

The video you posted above is from a different mode of failure: too much suction. Funny enough, this is exactly what you want in an M54 engine to reduce oil consumption.
The "BavarianE39 mod" is exactly that: creating a lot of suction to reduce oil loss from leaky piston rings.
This was from my 2001 530i, it had a failed CCV and the dipstick tube (original non-updated version) was clogged
 

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Discussion Starter · #80 ·
This was from my 2001 530i, it had a failed CCV and the dipstick tube (original non-updated version) was clogged
Do the BavarianE39 CCV mod (in Xoutpost forum) and move on.
It has been a few yrs and 10K miles since I did the CCV Mod on my 2006 X5 3.0i: oil consumption went down to zero, unbelievable mod (it used to consume 1 qt of oil per 400 miles!!!).
 
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