Xoutpost.com - DIY Solution to M54-M52TU CCV problems

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Quote:

Originally Posted by Bmwe5320023.0 (Post 1230953)

Thanks for the offer!
I think factory max is around 18 inHg
I'm thinking of using this gauge to measure
MEASUREMAN 2-1/2" dial, 1/4"NPT Lower, Glycerin Filled, Stainless Steel case, Brass Inside, 30inHg/-100kpa-0-30psi/200kpa https://a.co/d/aBk7onu

What's would be the easiest way to do it?
I'm thinking of just drilling a hole in the oil cap and then screwing that vacuum gauge unto it!

I have a cap that I drilled a hole in to previously test. That is what I will use. The vacuum was really low, so low it barely moved the needle reading psi. I think I remember reading somewhere that the vacuum was somewhere around 11 inches water column by design. That is roughly 1/2 psi.

Quote:

Originally Posted by Bmwe5320023.0 (Post 1230958)

If I understand correctly, the actual vacuum (negative pressure) in the system is the same, with factory CCV or without.
By factory, the CCV system simply blocked the manifold suction, so that the CCV Valve was controlling the flow basically, and not letting manifold intake pull at full force.
Without the CCV, intake manifold creates a lot stronger pressure because there's nothing stopping it.
So now the negative pressure must be trying to pull air into the engine from anywhere it can, like all the gaskets and seals. I guess they can't really leak, cuz the negative pressure is so high. How can oil leak outside if it's beong pulled inside? Yet at the same time, it must not be great for these gaskets and seals to be under so much pressure, they can probably get damaged by constantly being pulled inside the engine.
I'm not an expert and don't know for sure how it works.
By installing the PCV valve between valve cover and manifold, does it not restrict how much air the manifold can pull front the valve cover?
Or otherwise what's the point of that pcv valve?

The PCV valve does restrict some air, just not as much as the CCV.

A PCV valve is not designed to work in a closed system so it will open completely as soon as crankcase vacuum over comes manifold vacuum minus the PCV valve spring pressure. The only restriction is up until that point right after the engine is started or there is enough blowby (or leak) from the rings to close it again.

Quote:

Originally Posted by Xelo (Post 1192650)

I must revive this thread upon new findings regarding the amount of vacuum the M54 pulls after this modification.

In latest SIB 110308 BMW states the amount of pressure/vacuum inside the M54 crankcase must be ~16 mBar (that is 0,48inHg). As measured while using the FRAM FV345 PCV valve, the vacuum is 12-15 inHg (or +500mBar). That is over 30x the limit the engine was designed for, this is insane!

And this amount of vacuum is at idle ! Please imagine what letting off throttle/decelerating at 3-4-5K RPMs will do to the level of vacuum :yikes:
This will no doubtly damage seals/orings inside and deprive the oil pump of oil, lowering oil pressure for brief moments on decelerations.

I have not met another engine in the world where upon opening the oil cap that much vacuum is present. This is wrong and must be addressed as this modification transforms a Closed Crankcase Ventilation system into a Positive Crankcase Ventilation system, but without all the elements needed for such a PCV system to work.

Inside classic PCV systems/engines, there is a continuous air circulation inside the crankcase because there are 2 holes letting the crankcase breath: first one lets the blowby exit being sucked by the intake through the PCV and the 2nd one lets fresh filtered air inside the crankcase in order to: 1) limit the amount of vacuum being built 2) properly vent all areas of crankcase in a wide range of engine RPMs
Usually this 2nd hole sucks air from the intake downstream (after) of filter/MAF/MAP but before (upstream) throttle - where the vacuum is low when throttle is closed.

By removing the CCV (OK), plugging the dipstick drain hole (not OK) and rerouting the crankcase blowby venting directly into the intake (OK) you have designed an incomplete PCV system. One has to allow the block/crankcase to be vented with fresh air from a clean source otherwise it would be like sucking air from a plastic bottle: something/somewhere will colapse and those will be either your VCG or rear main seal.

By venting the block through a 2nd hole you are punching a hole in that plastic bottle you are sucking air out of: while the sucking is still there, the bottle will not collapse anymore as some small venting/air is let in keeping it vented.

If this worked for some of you it does not mean is a right thing, the engine was not designed for this amount of vacuum - and this is BMW's statement as you can see.

You need to provide clean measured source of air to the crankcase while using the PCV. This can be easily done through the vacuum F connector in the intake boot with a T connected to the dipstick previously plugged while a check (one way) valve is installed to prevent air/pressure from the crankcase going up to the intake.

Here's my test. So I just measured directly at the hose that goes into the distribution box that's connected to the manifold.
So manifold is pulling 16-17 inHG instead of 0.48 inHG?
Does the original CCV system then blocks the vacuum at the diaphragm and doesn't let it pull so much from valve cover?
I guess to confirm all we need to do is have someone with the stock CCV system measure the vacuum?
Which is probably going to be like bmw says 0.48inHG?
So on this case it's true, the vacuum with this mod is 30 times stronger.
Now how much vacuum is safe for the seals?
Just for fun I sucked on that gauge as hard as I could, and it showed 23 inHG lol! So it relative terms that I can relate to, it's not that much suction...

https://i.ibb.co/Y3m0qwL/20230630-161317.jpg https://i.ibb.co/3F7Bh0b/20230630-161950.jpg https://i.ibb.co/KzmKjgV/20230630-161526.jpg https://i.ibb.co/6Pb0MPs/Screenshot-...531-Torque.jpg https://i.ibb.co/f1fRbMY/20230630-162057.jpg https://i.ibb.co/0sNnWWB/Screenshot-...110-Torque.jpg
But it's probably enough to stop the oil consumption...
Here's CN90's picture, numbers are just examples.
BTW I wonder if CN90 is still around with thus mod?
https://i.ibb.co/VWT6zHC/Screenshot-...735-Chrome.jpg
Fifty150hs I think your mode is a bit different because you installed a catch can??

Quote:

Originally Posted by Bmwe5320023.0 (Post 1231011)

Mine is pretty much the same except the catch can is in line between the output of the PCV valve and the return into the intake manifold. The Cn90 mod runs the hose from the PCV outlet directly to the intake manifold. The catch can in my system just extends the hose from the PCV outlet and the inlet to the intake manifold. No difference in vacuum.

Sounds good, we've got same vacuum, that's good, you've had it for many years, gives me confidence :)
My setup I'd like cn90 then.
I drove around and according to torque app, the vacuum goes up to 27inHG, but often times, whenever you accelerate, it goes to only 1-2 or around that point.
We'll see what happens...I've got no leaks right now, so it will be easy to tell.

Checked my vacuum today. Put an oil cap on that I had drilled a hole in and plugged in a vac gauge. I was pulling 1" hg at idle. That's only about double the vacuum it's supposed to be pulling. It's more, but certainly not excessive.

Thanks for checking. I bet the oil catch can must be letting the air through. Or there's gotta be a vacuum leak?

Yes, there must be a leak somewhere. There is absolutely no way that a PCV is regulating the vacuum in the crankcase to 1".

Actually I forgot that I swore to myself never to post again in this ridiculous thread!

Quote:

Originally Posted by Bmwe5320023.0 (Post 1231034)

Thanks for checking. I bet the oil catch can must be letting the air through. Or there's gotta be a vacuum leak?

Catch can is sealed with an O ring. If I had a vacuum leak I'd be throwing codes. I'm not. The line essentially runs from the valve cover, through the catch can and into the intake manifold. When I first tested before the mod I got 1/2" hg vacuum. The system is definitely working as I get oil in the catch can. If I tested vacuum by porting directly into the intake manifold I would expect 17" or more.