CSL breather tube

[ethan]

One other option: you can keep everything. To achieve a longer corrugated hose you can either: 1) buy the CSL version and swap over the hose or 2) heat up your existing hose with a heat gun (slowly) and gently stretch it; there is more than enough length bunched up in the corrugations. I recommend the latter because nothing is required for purchasing. The former will still be cheaper than sourcing an air rail. If looks take precedence then swap out the air rail for a pre -04 version.

If, as terra says, the stock position of the valve is open, do you get a vacuum leak through the PCV valve running a CSL tune?

[repoman89]

The air rail is usually dirt cheap used, got mine on the old forum for $50 shipped I think and there was more than one listed for that price. The looks are one thing but as an engineer a non-functional piece with a non-functional plug sitting there staring at me would bother the hell out of me, so the rail was a no brainer.

[jbfrancis3]

One other option: you can keep everything. To achieve a longer corrugated hose you can either: 1) buy the CSL version and swap over the hose or 2) heat up your existing hose with a heat gun (slowly) and gently stretch it; there is more than enough length bunched up in the corrugations. I recommend the latter because nothing is required for purchasing. The former will still be cheaper than sourcing an air rail. If looks take precedence then swap out the air rail for a pre -04 version.

[Cubieman]

Great, well for appearance sake I think I need a pre-04' rail. I guess I'm in the market if anyone has one.

Although theres got to be a decent way to plug that.

[terra]

The default state of that valve is open. You'll have a vacuum leak if you don't either get a pre-04 / CSL rail or plug the vacuum port.

[Cubieman]

If you're going to be running the CSL engine software, then you have to delete it.

As far as deleting it would simply unplugging the wiring connector be enough? This would also assume I modify the CSL breather on the passenger side hose connection to connect up with the other smaller diameter tubing running to the valve.
Or I could cut and plug the rubber hose from the air rail to the valve and leave the CSL breather untouched.

[COVID-19]

What if you just buy one of those vacuum caps. (Or whatever they called)

[terra]

If you're going to be running the CSL engine software, then you have to delete it.

[Cubieman]

Well unfortunately I won't removing this eye sore or ill have one hell of a vacuum leak.
My 6/2004 has a different air rail with a place for this ugly/bulky breather setup. Was really looking forward to ditching this piece as well as not modifying the CSL breather. But thats cheaper than a new rail.

[Cubieman]

Makes sense.

[ATB88]

That little extra electronic valve was actually only on later model cars (I think sometime 2004 and later?). Earlier M3s just have a hose that's exactly like the CSL's, only shorter. Since earlier M3s don't have that valve I'm pretty sure unplugging it would have no effect in terms of CEL/DTC on a normal factory tune. But even if there was, you should be running CSL software anyway, and that wouldn't know what that valve is, so definitely wouldn't throw a CEL/DTC? So with that in mind, I would think that there's absolutely no point in retrofitting it into your CSL setup, as it won't do anything.

[Cubieman]

Doing a CSL box soon, I've got a CSL breather and had planned on modifying it to hook into the little tube/valve on a standard (US Spec.) M3.
After looking at pictures of different people's CSL box installs I've noticed the vast majority do not modify their CSL breather.
What effect does eliminating this extra tube/valve and unplugging the connection to the valve have as far a DTCs/CEL lights go?

Pics for clarity:

US Spec. :

CSL: