CSL breather tube

[Cubieman]

So is there really a definitive answer whether or not this setup with CSL Software will cause a vacuum leak? I've seen this valve left on other CSL airbox conversions.
It turns out ECS won't have a pre-04' rail for a few weeks and I'd like to start working on getting my airbox in tomorrow night.

Dura didn't seem to be having any issues running his setup.
As of now I'm just planning to go get some of those vacuum caps at the local auto parts store and cap off the bung on the rail to the valve. After reading through all the great info in this thread I'm still unsure about this valve.

I guess it comes down to this question: is the valve OPEN or is the valve CLOSED when not energized? I suppose when I've got everything apart I can blow through the valve and find out whats what.

[Cubieman]

So I took off the breather, plugged the crankcase side hole with my finger then sucked through the airbox side hole, that valve if definitely open.
So I would be led to believe that the bung to this valve on the air supply rail needs to plugged with CSL airbox/software, yet others say it causes no issues.

And I was also was reminded of the fact that motor oil tastes awesome

[terra]

The valve is definitely open when not energized. I guess question is does the DME output default to grounded or not. The CSL DME has no control over it, but if the output defaults to grounded, you might be okay.

[ethan]

And I was also was reminded of the fact that motor oil tastes awesome

👍. Same - really noticing the difference in this Ravenol additive package.

[heinzboehmer]

And I was also was reminded of the fact that motor oil tastes awesome

Lol. Blowing might have been better than sucking.

[jbfrancis3]

So is there really a definitive answer whether or not this setup with CSL Software will cause a vacuum leak? I've seen this valve left on other CSL airbox conversions.
It turns out ECS won't have a pre-04' rail for a few weeks and I'd like to start working on getting my airbox in tomorrow night.

Dura didn't seem to be having any issues running his setup.
As of now I'm just planning to go get some of those vacuum caps at the local auto parts store and cap off the bung on the rail to the valve. After reading through all the great info in this thread I'm still unsure about this valve.

I guess it comes down to this question: is the valve OPEN or is the valve CLOSED when not energized? I suppose when I've got everything apart I can blow through the valve and find out whats what.

Why don't you cap the air rail AND the small bung T'ed off the breather fitting (remove the small corrugated line). That way you can be at ease with everything.

[Cubieman]

Why don't you cap the air rail AND the small bung T'ed off the breather fitting (remove the small corrugated line). That way you can be at ease with everything.

I've got a CSL breather tube on hand, so I will remove the US tube/valve and cap the air rail. This stuff is going through my head all day! Although excited it's finally time to put it together.

[jbfrancis3]

But to answer your question, I think we're getting pretty close to the definitive answer, no?

Isn't the idle air valve (which is variable and PWM-controlled) going to compensate for the air coming from the PCV? It can compensate within reason, and this would be within reason.

All of the air mass will be calculated by the MAP sensor and IAT sensor, I believe. I think the DME looks at RPM targets to main idle with the correct fueling. This is my grossly oversimplified understanding/mis-understanding of course - feel free to correct.

[Cubieman]

But to answer your question, I think we're getting pretty close to the definitive answer, no?

Isn't the idle air valve (which is variable and PWM-controlled) going to compensate for the air coming from the PCV? It can compensate within reason, and this would be within reason.

All of the air mass will be calculated by the MAP sensor and IAT sensor, I believe. I think the DME looks at RPM targets to main idle with the correct fueling. This is my grossly oversimplified understanding/mis-understanding of course - feel free to correct.

Very close, and you are above me in the understanding of this system so your insight is quite welcome. I'm just not 100% this valve will not create issues.

Now that the MAF is gone, if the valve lets in air I suppose you could no longer consider that to be unmetered air and the ICV/MAP should be able to figure out whats going on as I think you just alluded to.

[ethan]

But to answer your question, I think we're getting pretty close to the definitive answer, no?

Isn't the idle air valve (which is variable and PWM-controlled) going to compensate for the air coming from the PCV? It can compensate within reason, and this would be within reason.

All of the air mass will be calculated by the MAP sensor and IAT sensor, I believe. I think the DME looks at RPM targets to main idle with the correct fueling. This is my grossly oversimplified understanding/mis-understanding of course - feel free to correct.

For the system to function correctly, you need variable control over the position of the PCV. That's why it's an electrically-actuated valve in the first place, and it's why earlier cars didn't just tee the oil separator outlet to the airbox and vacuum at the air rail.

If you're on a CSL tune, it's not aware that the PCV is even there, so my bet is if the car runs normally, then terra's hypothesis is right: The harness is probably powered by default such that even if the ECU isn't aware of the valve, turning the car on snaps the valve shut and keeps it that way. Then the system functions as if it were an earlier car (e.g. a CSL) having its oil separator connected only to the airbox. I'd love to test that but my cars are '01 and '02, so I don't own a PCV-capable wiring harness.

[Cubieman]

Wonder if I could back probe that connection, I'll check. Hopefully I'll have my airbox installed by Sunday is the goal.
If I can back probe the connection I'll test stock than test again after installed CSL DME.

[repoman89]

For the system to function correctly, you need variable control over the position of the PCV. That's why it's an electrically-actuated valve in the first place, and it's why earlier cars didn't just tee the oil separator outlet to the airbox and vacuum at the air rail.

If you're on a CSL tune, it's not aware that the PCV is even there, so my bet is if the car runs normally, then terra's hypothesis is right: The harness is probably powered by default such that even if the ECU isn't aware of the valve, turning the car on snaps the valve shut and keeps it that way. Then the system functions as if it were an earlier car (e.g. a CSL) having its oil separator connected only to the airbox. I'd love to test that but my cars are '01 and '02, so I don't own a PCV-capable wiring harness.

You can probe it in the DME box if you can manage to stick a multimeter lead to pin 52 of X60003 while it’s plugged in (can’t remember if that would be possible). Other end is one of the big Molex connectors in there looks like. I snipped off my breather valve connector and need to remember to pull these two wires one of these days.

https://www.newtis.info/tisv2/a/en/e46-m3-cou_200506/wiring-functional-info/power-train/engine-control/digital-motor-electronics/controller/crankcase-ventilation-valve/uHDGNAK

[duracellttu]

For the system to function correctly, you need variable control over the position of the PCV. That's why it's an electrically-actuated valve in the first place, and it's why earlier cars didn't just tee the oil separator outlet to the airbox and vacuum at the air rail.

If you're on a CSL tune, it's not aware that the PCV is even there, so my bet is if the car runs normally, then terra's hypothesis is right: The harness is probably powered by default such that even if the ECU isn't aware of the valve, turning the car on snaps the valve shut and keeps it that way. Then the system functions as if it were an earlier car (e.g. a CSL) having its oil separator connected only to the airbox. I'd love to test that but my cars are '01 and '02, so I don't own a PCV-capable wiring harness.

I can test this after I get my car back together if you tell
me how. Is it as simple as taking off the PCV connector and probing the two leads? Checking one/both for continuity to ground?

[terra]

I can test this after I get my car back together if you tell
me how. Is it as simple as taking off the PCV connector and probing the two leads? Checking one/both for continuity to ground?

One of the pins will be ignition switched +12v, the other should be a DME switched ground.

I suppose now that I think of it, you could just move the pin at the DME end to a ground if you want to keep things looking stock without having to worry about what the DME does with that output.

[Smitsky089]

Any conclusions on this one? I've been running Evolve's CSL airbox with Evolve's Alpha-N tune for 2 years and don't think I have any vacuum leaks while retaining the stock post-04 air rail/connector.