While I agree with the above points, I think the factory AOS system, in good operating condition, is good enough. The efficiency gains, and other benefits of the catch can are likely small percentage improvements that aren’t noticeable. And if you can’t notice a difference in drivability and performance, is it worth messing with it in the first place?

 

Depends on whether you like taking your intercooler plumbing apart to drain accumulated oil, or not doing that and it getting to the point where in high vacuum situations it sucks oil into the intake and blows smoke out the back and fouls those spark plugs. I'd rather keep the combustion more pure and efficient and the intake tract free of oil.

Is it absolutely necessary - nope, is it better than not doing it, yup.

 

Do you remember the hose size? I have 06 ctts

 

Link doesn't work - at least not for me.

 

I re-inspected my whole catch can set up again. New vibrant performance braided hoses with internal springs to prevent collapse I was having before with the Conti hose, and a Mishimoto compact catch can.
I started blowing through the hoses to check for restriction, the hoses by themselves where fine.
Then I attached one at a time to the Mishimoto, the in hose into the can, I could easily blow. However with the second out line added back on the can and blowing through the in line, or blowing from the out line into the can, there was a lot of restriction.
I took the can apart, removed the bronze filter, cleaned it, and tried to simply blow through the bronze filter, and it was tough. This filter is very restrictive. To me this would seem to be bad for the PCV/AOS system, so I started searching the internet.
I found these 2 discussions:
https://www.ft86club.com/forums/showthread.php?t=146174
check out the video, where this guy does a comparison of the crankcase pressure in crease due to different catch cans. The one with the bronze filter is exactly like my Mishimoto (shows the bronze filter at 6:30). He also mentions how Mishimoto changed the design for a Cummins application and removed the bronze filter set up all together, and went to baffle and mesh design to eliminate check engine codes assumed to be related to high restriction of the bronze filter type arrangement and impact on the engine operation.
https://f30.bimmerpost.com/forums/sh....php?t=1791329
In another thread, this guy had some issues with his Mishimoto/bronze filter on a BMW.
Now I dont know for a fact this is my issue with my poor running, higher oil consumption, more smoke recently, I thought it was due to the previous hose collapse, but I have since return my set up to stock.
Something to think about at least.
I might try a higher flowing can, one without the restrictive mesh filter. I suppose you can then trade off oil capture, but I would rather have some and less potential draw backs to higher than normal back pressure/crank case pressure.

 

You know, I never thought about this aspect of it. If the catch-can is restrictive and it generates a lot of crankcase pressure, not only might it be starving the engine for the air it's expecting back causing it to run rich, but it could generate excessive crankcase pressure which could then create leaks in things like oil pan seals.

That video showing the bronze filter resulting in 3x the crankcase pressure vs the stock system is significant, and I think that test was done at idle too. Once there's more air moving through and restricted, it might be even worse.

I haven't noticed any operation ill effects from my setup but the dual chamber Verus AOS I'm using is a very different design than many of the catch cans where it's the shape of the airflow channels and the media that's in them which pulls out the oil, but may not be restrictive to the air flow, especially since I've split it into and out of the AOS where the potential restriction could be.

I have no data on how many cubic feet of air moves through the valve cover AOS system or what the Verus AOS is rated to handle. Probably should have looked into all of this first, but so far, my dumb-luck setup seems to be very effective (1.75 oz captured every 500 miles) with no ill effects to performance.

 

Agreed, I went back an looked over what cans others were using, and noticed yours, think you used the same on your 928 or other Porsche. Yeah, its a chambered design, so no media to have to be forced through, you are probably fine!
I might try my Mishimoto without the bronze filter, and maybe just put some other less dense media above the baffle plate, and see if it catches anything, and of course blow through it to make sure its much easier.
Might be to tough to judge now that its summer, where the condensing is less in the can since its relatively hot as well.

Again, I have a different set up, by my ill effects were not noticed for several months, over the winter it was fine, and started to show themselves this spring. I honestly believe the DME started adapting to this change over time and eventually got so far out of wack that I began to notice. Never had a check engine light, and my Icarscan has been reading all clear. Just a hypothesis.
I left the batter disconnected over night and she is back to her old self with the OE AOS elbo back in place.

 

Yep, had really good luck with the Verus on my 928 and why I wanted to use it again, but it's used slightly differently on the 928, where I'm venting the crankcase to one chamber and the cam towers to the other, have the drain line tied back to the sump so never have to drain it, and have it vented to atmosphere instead of back to the intake.

 

Get rid of the sintered bronze filter. I used coarse stainless steel pot scrub pads in mine. All you need is a surface for the oil vapor to condense on.

 

I found this $10 short emissions hose on Amazon that could help when hooking up catch can. I was gonna use factory 90 degree connector on the AOS, and this hose on the other side, cut off the end at desired angle and run hose from there

 

thprf, were would I put the scrub media, above the baffle and close to the old bronze filter, or below the baffle and down in the can?

 

I'd put it above the baffle. You can even remove the baffle completely as the stainless mesh is taking it's place. That is what I did.

 

I used the Stainless scurb pads too, I just filled the catch can with it.

 

Ok, Im gonna drive for a few weeks with it back at stock setup, to get a baseline again of "running good", then I will reinstall my Mishimoto with the scrub pads and hope for no change!

 

Rate my $35 setup

* When purchased it was missing all decorative covers from under the hood and also from under the engine, I decided to leave it like that as engine bay feels very hot even without covers