I’m not sure if this was mentioned before (used search and nothing came up), the m56 engine from a sulev e46 has a valve cover that will fit the m54/m52tu engines and the valve cover is aluminium with an inbuilt ccv. Thereby eliminating the need for the stupid ccv system under the intake manifold.

The only issue is that the VC is only available in the US (available from eBay for about ~$250) and some modification is required; ignition coils change to the push in ones, (IIRC 2001 - 2003 X5 models have the bolt in ignition coils) this requires a change to the push in coil harness.
And the ccv diaphragm + cap is somewhat difficult to find. There is a huge thread on another forum where someone made an aluminium cap which works fantastic.
Also, the dipstick tube needs to be capped off and the plumbing for the vacuum lines from the intake manifold to the VC needs to be changed.

All easy work though.

It’s mostly a straight swap and the gain is amazing. I’ve been running my m54b25 with the m56 valve cover for over a year now with no issues or headaches.

Here is a photo of it;
https://uploads.tapatalk-cdn.com/202...60d12a2f87.jpg

This was something I had considered when I bought my X. Catch cans are great, I've had them on other cars, but this would be a maintenance-free solution. I still may end up trying this someday.



Were there any twists in the project, anything that didn't go as expected, or any hidden costs?

The only real big problem was my diaphragm was buggered and I had to find a different solution, the only one I found at the time, was a Russian made one on eBay, but taking that ccv cap off was also impossible without breaking the tabs, and replacement for the cap was not available at that time. Now it is!

I would recommend getting the aluminium cap and Russian diaphragm with the VC before replacing the VC, also if you reside in US, go to a pick n pull to get the VC, I found one (after 4 months of searching) and got the whole kit for $100 (VC, 2 sets of coils, harness, dipstick tube, gaskets and VC vacuum hose)

You can find the cap if you google m56 valve cover on m54 on a forum. (I don’t want to link it because I don’t know the policies here yet).

The other issue I experienced was that my VC studs (screwed into the head) were stretched, and the VC was not sealing correctly, so oil was dripping on the exhaust, so I ordered new head studs and replaced them, and now it is sealing good. I didn’t read anyone else having this issue.

Definitely get new VC gaskets and grommets (for the nuts)!!!
The m56 VC gasket and spark hole gasket is different from the plastic VC, it’s flat, it’s also metal covered in rubber. The grommets are the same.

The last bit was the vacuum hose plumbing, what I did, I left the thin tube running along the intake manifold, I removed the hose off of the fitting for the intake splitter, added 3” long vacuum hose ran it through where the original ccv hose went, added a 90° fitting at the end, then ran another 3” vacuum hose from the VC to the 90° fitting, this makes it look OEM and functions perfectly. If you run the hosing without the 90°, the hose will kink and will cause issues (no air flow).
Hose is 5/8th ID, none collapsible silicone.
The 90° fitting is 5/8ths brass barb.

I forgot to mention in my previous list of items, get the VC to intake manifold hose, you will need the quick connect for the VC, it is different from the composite plastic VC. (In the top left corner of the picture below).

The below shows all the prices I needed, I did not replace my dipstick tube, I just capped off the return feed for the original CCV system. Also, the harness will not need to be changed if you have the push in coils, I just transferred. The clips that hold the harness over (the tiny silver clip on the vc below).
https://uploads.tapatalk-cdn.com/202...431a57d233.jpg


Separate notes; the three clips next to the spark hole gasket, lower right, those go onto the VC lip on the right, they hold the O2 sensor cables.

I can take photos of my install if anyone wants.

Sorry about the long post but I’m adding literally everything tiny thing I did to make it as OEM as I could, fit, finish and function.

i am curious too.

For those with this mod and go for smog test (such as California, Illinois etc.),
any issues with smog test?

My guess is that: it is probably OK.

I'm going to be getting one this weekend. If they fail me because of it, I'll be going back to the stock system. The CCV is still there. I would just need to replace a couple hoses. I'll let you know.

For those who went for emission testing, do you re-install the cosmetic cover
to hide the "Art Work"?

PS: I have never this (CCV Mod) being an issue during smog test.
All the smog stations care is emission pollutants, if the tailpipe output is clean,
then you are OK.

I put the cover on. I also used the factory elbow coming off the valve cover to try and keep it looking as stock as possible. Only thing that gives it away, besides the catch can hanging in the engine compartment are the non-factory hose clamps that are visible. I could have replaced those with factory style, but I was lazy.

Sometimes I wonder the intelligence of these smog inspectors...

Let's say a driver modifies his/her car such as this.
Of course it is not factory (it is better than factory IMHO).

So what, as long as the tailpipe emission tests are good.
I understand why they look into the engine compartment: the purpose of this should be to look for broken hoses that can potentially contaminate the environment.
If the hoses are fine and all they see is a mod, so what...

If they ONLY focus on the tail pipe, then what we did as a mod should not matter...

In New York, they don't open the hood, just plug the computer into the OBD port.

This state requires them to look under the hood. I think if left to their own devices the smog guys would just hang the sniffer in the tail pipe and run the test. Less work for them.