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DIY: CCV Delete and Moroso Oil Breather Tank Install

70K views 69 replies 29 participants last post by  gosystem 
#1 · (Edited)
This is a DIY for the removal fo the CCV system in entirety and the installation of a Moroso oil breather tank in it's place. I wanted to remove the stock CCV system as it's another thing on the car that I look at and think 'junk'. It was also worn out and letting far too much vac be on the crankcase. I also wanted to no longer recirculate oil vapours into the engine.

I used the two studs on the suspension tower that is on the exhaust side of the engine to mount the breather tank. I think these are the same studs that are used for the secondary air thingy but I'm not sure, my euro car doesn't have this.

Finished article:



Parts required:

Moroso 85465 breather tank (has a 12AN fitting)
Rubber caps (7x) (see link here)
Hose clamp 46mm thin type (1x) (see link here for the ones I used)
Hose clamps 22mm (7x) (see link above for the ones I used)
M6 nuts (2x)
M6 washers (2x)
3/4" ID oil resistant hose (~0.5 m) (I used Aeroquip AQP)
12AN straight hose fitting
3/4" elbow









Step 1:

Step 1 is removal of the stock CCV system. I haven't documented this process but it is relatively straightforward. We will be roughly copying this diagram (shamelessly stolen) but only keeping the connector which is on the valve cover. The dipstick return will be capped off.



Here are some pictures of the 2 CCV torx bolt locations just to help:





You can see where i cut the stock CCV with a hacksaw for easy removal:



Step 2:

Step 2 is capping off the dipstick return and the 6 inlet runner bungs.

This is the cap and hose clamp on the dipstick, which I removed from the sump (big mistake). I left a small piece of the original hose on the dipstick to make the diameter larger to suit the cap. If you remove the dipstick from the sump (by pulling upwards after removing the bolt from the bracket) it will be difficult to re-fit it with everything else in place. I would seriously recommend capping it off in-situ.



These are the caps and hose clamps on the inlet runner bungs. You could cut the caps down some so they sit lower but I couldn't be bothered.





Step 3:

Step 3 is the installation of the oil breather tank. The first job is to mount the bracket on the studs using the 2 washers and nuts. Be careful not to cross-thread the nuts as the threads on the studs aren't amazing. You may need to bend the bracket slightly to go over the 2 studs.

You could alternatively mount using the lower stud you can see and a plastic expanding-type clip where you can see a plastic fixing. This would work and you would have clearance to the frame rail underneath however you would have no chance of draining the tank in-situ. Also you would need a 45 or 90 degree 12AN fitting perhaps.



Install the tank within the bracket:





Now assemble the hose and attach to the tank and valve cover. Use dish washing liquid to lubricate the push-fit fittings! You can alternatively run it the other side of the oil filler and attach to the underside of the strut brace if you have one. The way you see below allows you to fit both original covers though.





You can see how the filter has a deep base, this gives around 5 mm of clearance between the top and the hood. I cut it down to half the size to increase the clearance to 10 mm. This is why you need a thin type hose clamp, not the one supplied with the tank



Job done :craig:
 
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#7 ·
That's one of the main points, it's just another thing on the car that is junk by 60k miles and is a pain to change. Also the idea that if the diaphragm fails it can suck up the oil from the sump is a real joke.

The other points are that I don't want to burn the oil vapours and don't want to be returning crappy oil/water mixture or fuel from blow-by back to the sump, diluting the oil. It may 'use' slightly more oil with no return line but I'm not worried about this.

I really like this idea, have you had any trouble? CEL or otherwise?
No CEL, it's purely a mechanical system.
 
#9 · (Edited)
Very well done!

However, A vacuum in the crankcase is beneficial in our case since our engines employ the use of low-tension piston rings.

That small amount of vacuum helps the piston rings seal better. among other things.

A catch can setup that creates vacuum in the crankcase would be the ideal setup.

The vacuum inside the crankcase is only about .5 inHg. I have a reason to believe that increasing the vacuum between 6-8 inHg will net some HP gains.
 
#22 ·
This is an interesting mod. I am definitely going to research this. I live in so cal, so I don't have the cold weather that seems to play a part in ccv failure, but, it's definitely cool that there may be viable options for this. Thanks for posting the info.
 
#27 ·
I've changed mine about a dozen times since it's gone in.

I've since removed the PCV valve and inline filter. The filter was getting too dirty too fast, and would have to be replace monthly.

I didn't like the fumes going in behind the MAF, essentially creating a vacuum leak. So I plugged that hole in the intake elbow, and ran the outlet line from my catch can down into the fender well. So now I'm just venting to the atmosphere.

I reset my adaptations, and the car immediately ran much better. Thought it was just my imagination, but it's been weeks, and the low/mid range is much better. I think that I was right about the vacuum leak. Also, having it vent lower to the ground keeps the fumes from entering the cabin when you are sitting at a stop light. And now I'm gathering a lot more in the can. Which shows how much I was sucking into the engine. Yikes.

I can't agree or disagree with the low tension ring comment. But it is running better than ever right now, so I'm going to stick with this.
 
#33 · (Edited)
completed my setup inspired by the OP with some slight differences...

instead of a catch can i used an oil separator from the m5.
I cut the rubber line that went to the dipstick from the ccv, extended it and connected it to the bottom of the m5 oil separator so that the oil returns to the oil pan like it does with the stock ccv system.

Drove to work and back and it seemed smoother. It was cold this morning and no stumble like i have been having previously. Fingers are crossed.

There was definitely a ton of crud inside the tubes going to the ccv before doing this so who knows what it is the ccv iself.





 
#41 ·
Is the purpose of the return lines and the distribution block just to return the air to the intake for emission control?

Would this M5 OS work just as well if I retained the distribution block and just ran some hose to it instead of using the air filter?

Pos/Neg for either method?
 
#45 ·
Dan, my CCV does not have a vacuum line going to it, it has a cap. I don't know if our (US) CCV works different than the European one.
 
#48 ·
I updated my oil separator wit hthe clod climate version and its still freeze with cold weather. I'm looking forward to this mod! Waht are the long term effect of running the crankcase with no vacuum? Can it bring some failure?!?

I put 800+$ in clod climate OS (did it myself), oil flushes wit hoil cleaning stuff and +++ and it still freeze. Its time to remove that shitty system. BMW has a tendency do do simple things complicate...
 
#50 ·
Sorry to hear about this. I am not aware of any concern with running no crankcase vacuum, excluding what newe46fan said about low tension piston rings.

Doing it on a M54 and the E39 M5 OS? It could get the throttle a bit dirty... but how much? Its done in a lot of other cars, including M5. Can it be that bad? It would have to be connected after the MAF, since you dont want to gum it.

You would keep the vacuum in the crankcase and this would not create a vacuum leak in the intake since you are before the throttle body. Also, you would not create any fumes and oil smell.

What do you think?!?
Sure this would work, I think you are going to get some dirtiness in the throttle and intake manifold but probably not much more than what you get with the stock system (and that can be quite a bit). But with your method you are returning the water vapour to the sump as well, which is one of the benefits of venting to atmosphere, because when the water in the oil is heated up sufficiently it can escape freely and either condense in the tank or escape out the filter.
 
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