Oil Breather line removal & Oil Breather Cap
 

I have read a ton of threads where users have installed catch cans and tried to cap off their oil breather line and they get crazy noises. In my case the noise was happening, but only because my oil breather cap that I put on seemed to have a pressure valve in it.

I am not sure why it has this restrictive cap on it... Could it be to stop any oil that may splash up to not get on the filter? I am not 100% sure, but in the end it was preventing my engine to properly get the air flow it needed with the oil breather line capped off.

But overall the entire reason for this is to remove the 2nd way oil can get into your intake line and into your valves. I think most users do not think to remove this line, but I feel it is important to make sure your engine runs clean and to prevent long term damage that can and will happen to your engine.

Here is the breather line that you need to remove. It is easy to identify as it is the only other line that plugs into your Cool Air Intake. In my case I have a K&N CAI.

http://i714.photobucket.com/albums/w...ps721e7455.jpg

While this is a breather line and is sucking air, it has been seen time and time again that oil finds its way through this line and WILL dump oil into your intake.

This image isn't very clean, but you can see the oil that dripped into my intake tube after just a few months of driving. I found oil in the tube and on the Throttle Body which in my opinion is a bad thing.

http://i714.photobucket.com/albums/w...psbfe85a0c.jpg

I know this image isn't showing much, but that is just what was in the tube that dripped. Think of the drops that feel and just got sucked into the engine.

So to stop this, I purchased a 3/4" high heat plug and a brass plug to plug the little hole in my K&N Intake.

I removed the long Breather line as seen in this image and pulled off the 4" long rubber tubing to use to hold the plug and cap the old breather inlet on the back side of the engine.

http://i714.photobucket.com/albums/w...ps3f3da1bb.jpg

http://i714.photobucket.com/albums/w...ps6ddd60a2.jpg

Once I capped that off I installed the oil breather cap and the brass fitting into my CAI to seal it off.

http://i714.photobucket.com/albums/w...ps66ce062e.jpg

Now this is when I found out about what i think is a pressure valve on the oil breather cap. As when I started the car you could hear a high pitched noise that sounded like sucking and it quickly got louder to the point of me saying 'WTF'. I quickly pulled off the cap on the old breather inlet and you could instantly hear it gasp for air and the noise went away.

This happen each time I started and turned off my car... I used a OBD II reader and the car was also throwing an error for low pressure in the engine. I should of captured a screenshot of it on the Torque app :(

But that was when I decided to look at the breather cap I was using. When I took it off, that is when I noticed it had this brown inlet that had some sort of metal piece on the inside of it.

http://i714.photobucket.com/albums/w...psc2ad2c81.jpg

This piece sat flush with the black plastic and when I blew into it our tried to suck air through it, it seemed to be restricted both ways.

I am sure this is by design for once it is under pressure, but that noise was terrible... I took a pair of pliers and simply pulled the thing out.

http://i714.photobucket.com/albums/w...ps32ce714d.jpg

I used a shop knife to clear out some of the glue and residue that was left behind... but after doing that and putting the cap on, the noise was gone!

Overall I am not 100% sure I should of done that, but it fixed the issue and the error that torque was showing is now gone.

:pop2:

OP, I had the same issue with noise as you when I put my RX breather on and removed the stock clean side breather tube. I ended up putting my stock setup back in place as I was afraid I was going to wreck a seal somewhere with the excessive vacuum in the engine.

The problem with removing the check valve, as you did, is that the valve serves 2 functions. First, it prevents crankcase gasses from venting to the atmosphere, and second it is supposed to meter the incoming air. Since you've removed this meter, you now have unchecked airflow entering that breather, which is eventually drawn into your intake manifold via the PCV system.

The problem is that this air does not pass the MAF sensor and is therefore unaccounted for by the ECM. This can screw up your fuel trims and cause issues.

Supposedly some were able to get replacement breathers/check valves to remedy the issue, but in the end I decided it wasn't worth the hassle and just removed it.

I've been periodically checking my intake tube for signs of oil ingestion and haven't seen any yet, although I did have some prior to installing my catch can and drilling out my PCV valve.

Well, we shall see what may or may not happen. But in looking at performance I am only seeing good things and no errors popping up. Considering the air is coming from the same place (under the hood just above the CAI) I don't see how this will harm anything in the long run, especially now that 0 oil is able to get in through the CAI into the TB.

It's not the quality or origin of the air that is of concern, it's the fact that in stock form that PCV intake air is drawn AFTER it has passed the MAF sensor, so its volume is accounted for by the ECM. The breather with check valve is not, but is metered to stay within the parameters that the ECM can adjust for, based on feedback from the O2 sensors, etc. Without the check valve this unmetered air can exceed those parameters, then you can have problems.

Maybe you never will, but I wanted to get that information out there as it seems you're advocating removing the check valve, which may not work as well for everyone as it is for you.

The problem is the check valve is not breathing at all. Took it down to chevy and the tech mentioned the way i have it should be fine.

Anybody else have a take on this?:popcorn:

Take a look at Ted Jannetty's posts toward the end of this thread: http://www.camaro5.com/forums/showthread.php?t=309513. Sounds like he basically recommends using the stock setup over any breather.

I gave up on the breather and ordered the 1LE separator from Maureen at Rodgers.

When I had my cobalt SS I did a turbo swap (mine was the supercharged version) the car ran fine but after some time I got a breather used that in place of my oil cap (which had no check valve) and from the minute I drove off it was a big difference, like the car shaved a few pounds, everything was smoother and it ran a whole lot better. Now I know it's not a camaro and it was a 4cyl car that was not direct injected but wouldn't the same concept apply? This is the first time I have ever seen a check valve in a breather for a car. Plz let me know if im missing something.

ive seen that thread before but many cars run breathers so i dont see why the camaro cant or doesnt benifit from it.

You asked for another take, I pointed you to one from a very reputable source, which includes an explanation as to why the Camaro might not benefit from a breather that pulls unmetered air without the MAF sensor seeing it.

Or are you looking for a take that tells you what you want to hear?

Is someone catching feelings?? all i said is that i have seen this thread before, no need to get smart.

I'm not "catching" anything.

You said more than just that you'd seen that thread before. You also said that since other cars can run breathers that you don't understand why the Camaro can't benefit from one, even though the thread you say you've read contains a clear explanation from a respected and knowledgeable source as to why the Camaro shouldn't run one.