DIY Solution to M54-M52TU CCV problems

[ramp]

That looks real good. On mine I have the pvc valve tilted up slightly maybe 25 degrees, to let gravity help with the valve. Mine works like a charm. Great write up as noted.

[geobrick]

951 miles since doing the ccv replacement and it seems there's no oil consumption so far. I'll post again when I've got more miles on it.

[ramp]

I've shared this ingenious repair to a couple of BMW drivers.

[cn90]

I did this mod and it works great, zero oil consumption, so no complaints.

Question re decommissioned system...

1. I leave the Oil Trap alone b/c it is not sucking any oil or any air (I blocked the end of the hose where it joins the valve cover).
So is it OK to leave the Oil Trap in there "forever"?

2. The Return Hose ---> Dipstick Housing, this hose can break with time but since the Oil Trap is decommissioned, is there any harm of ignoring this hose? Let's say it is broken but you ignore it, any issues?

[geobrick]

I've got 2,228 miles on the car after the CVV removal and it looks like the oil's down about a 1/4qt.

I still haven't replaced the valve cover gasket which I suspect has a leak. I don't see any oil on the ground yet but I do smell burning oil in the cabin after long periods of highway speeds at about 70mph (after exiting the highway or slowing in traffic). That could be a contributor to the 1/4qt drop. Either way it's a huge improvement over what it was before removing the CVV.

[cn90]

- The modification I posted previously works just fine for a cost of $30 for parts.

- To plug existing system hoses: as long as you have some rubber material to plug any factory open hoses, it is OK. The idea is to de-commission the factory PCV system.

[Xelo]

CN90, could you please be more specific as to how you've plugged this original open ends of the CCV hoses (marked with big red arrows)?

As we know, open end as female - meaning you had to insert something into them, but how did you make sure it is tight/snug ?


Thanks !

[Xelo]

Hello again,

I am planning to do this modification also (including a catch can) but after days of studying I've stumbled upon one issue that has not been adressed (or addressed too little).

There are 2 versions for any PCV system: open and closed.
Open ones are venting the blowby gases to atmosphere, closed ones (as in this case for the M54s) are venting the "filtered" air back into the engine through the intake manifold.

Now comes problem #1: this "filtered" air is not measured .

MAF measures air coming through the intake manifold, but the one coming back from the valve cover through this modification is routed back into the IM AFTER the MAF (through distribution cover) - so there is a surplus of air going to the cylinders, although the ECU has measured less and O2 sensors will measure more.

This will cause crazy fuel trims.

Any schematic of closed PCV system on the net is described as having a venting hose coming from the air filter (so metered air) which allows the crankcase to breath.

See examples below:







Returning to the case of M54 engines: OE system does not have a supplementary/aditional valve cover breather as I remember. The only port of the VC is the one going to the CCV.

So this raises so many questions:
1) Why does the OE M54 CCV system does not have a breather allowing the crankcase to draw air from the intake
2) Would this breather be a good idea as it still allows vacuum but also protect engine seals ?
3) Where would the best connection for a breather be ? I have heard a case where the guy connected a hose from the vacuum F connector in the intake boot to the oil dipstick. If so, would this need a non-return valve (for the improbable case oil from the crankcase/oil pan would come up and flood the intake) ?




My take on this:

[80stech]

Good for you for trying to think things through and you are justified having some concerns, but you have some errors in your information. One big problem is that you don't have a diagram of the factory CCCV system. A CCCV system is NOT a closed PCV system. Also, I think it would be good if you started a new thread on this.

[Xelo]

Umm, sorry, but could you please me more specific about the errors ?
My drawing explicits exactly what you guys are talking about for some time: transforming the CCV into a PCV.