What is this thing on top of my fuel rail?

[ImolaM3Vert]

So I have this thing connected to my fuel rail and vent. There's also a wire hooked up to it. I've talked to a few people and they said they have rarely seen them. My theory is that it's a weird California emissions thing since the car was delivered there. I need to delete it so I can fit my new ACS strut bar on. I have unplugged it for now and have noticed nothing different with my M3.

The part number is "1435982". I've got a picture attached below. If anyone has any insight to what this is I would really appreciate the knowledge since nobody really has any idea

https://imgur.com/a/826rduc

[Mr.wReckless]

I wonder if that's got something to do with the brake booster vacuum assist sensor thingy? If so, I've seen that blob before, but some cars has it right next to the DME box and some have it on the fuel rail.

[Cubieman]

It is indeed an emissions item found on later MY cars, its a solenoid involved with your PCV system.

You can buy an earlier MY air rail without the port (or cap off the port) for this and also get a different earlier MY crankcase tube (or modify your existing) . Your DME will still be wanting to communicate with the solenoid so it's possible you may have to code it out or it could create a CEL, if you ever go CSL it's easy to ditch be because the euro software doesn't communicate with any such solenoid.

[repoman89]

I wonder if that's got something to do with the brake booster vacuum assist sensor thingy? If so, I've seen that blob before, but some cars has it right next to the DME box and some have it on the fuel rail.

That’s a different check valve, we all have those. The valve above the fuel rail came on 04+ (05+?) cars and can be safely deleted with an older fuel rail and hose line as stated above, plus deleting the CEL or running different software. I got a used rail here when I did my CSL conversion and snipped the plug off + capped off where it comes out of the wiring harness.

[BigRussia]

Ah that thing, I made a post about this very thing a while ago, i think on this forum not M3F. It was cause I was considering installing an Oil Catch Can and that thing was adding to the complexity so was curious what exactly it did and why the later cars had them.

But what's weird in my case is that my car is a MY2004 (Prod Date: 2004-07-15) with all original drivetrain, but has that thing which everyone else was saying only MY05+ cars have. I guess mine was one of the first 2004 run to get it. But yeah beyond that dont know much else about it. Looked up converting to early style but figured not worth the time and tuning effort for me.

[Cubieman]

Ah that thing, I made a post about this very thing a while ago, i think on this forum not M3F. It was cause I was considering installing an Oil Catch Can and that thing was adding to the complexity so was curious what exactly it did and why the later cars had them.

But what's weird in my case is that my car is a MY2004 (Prod Date: 2004-07-15) with all original drivetrain, but has that thing which everyone else was saying only MY05+ cars have. I guess mine was one of the first 2004 run to get it. But yeah beyond that dont know much else about it. Looked up converting to early style but figured not worth the time and tuning effort for me.

ECS lists the cutoff at 9/2004+ for rails with the solenoid, mine is 6/2004 and had it as well.

[ImolaM3Vert]

Cubieman Thanks for the info. I really appreciate the insight. Is this something I could code out with INPA or something. Or does this require a full DME flash? Because if it requires a DME flash I'll just go ahead and convert my car to MAP since I plan on a CSL in the future

[Cubieman]

Cubieman Thanks for the info. I really appreciate the insight. Is this something I could code out with INPA or something. Or does this require a full DME flash? Because if it requires a DME flash I'll just go ahead and convert my car to MAP since I plan on a CSL in the future

I'm sure NCS could do it but unfortunately I do not know the module or parameter you would code for this one. If you are going CSL/MAP in the future I would delete it at that point, a earlier model air rail and CSL crankcase breather would be the easy/clean way to do it but just know you can modify your existing hardware to save some $.