Catch Can Install?

[RIP98GTP]

Hi Everyone!
Happy New Year and I hope that your Holiday's were wonderful!

Quick question... Oil catch can on the 2012 GS - LHU engine.
Should I or shouldn't I?

What are the MAJOR Pros and Cons for such an install?

I have been seeing a lot of buzz about this. If it is a must do, what brand can should I get?

Thanks!

 

[GSTurbo]

What you need is a Powell air/oil separator. Do a google search, and it should bring up posts on the Cobalt forums about it.

A generic catch can will not prevent valve coking on a DI engine.

 

[Handy_Andy]

The idea of the catch can is to "catch" any oil blow-by that may occur, and instead of the stock setup routing it back into your intake, it gathers in the can so that you're not feeding that back into your intake. The theory is that our direct injection engines are more susceptible to carbon/gunk build-up on the intake valves because whereas regular fuel injection has the injectors squirting gas right on your intake valves (and effectively washing them), DI engines just have air and the occasional splat of blow-by go over them, with the oily blow-by baking itself to your valves. So the "theory" behind installing a catch can on a DI engine is that it will prevent this gunk build up on the valves, and with turbo DI engines the blow-by can be worse (especially at full boost).

There's a lot of opinion and hearsay about catch cans and their effectiveness, because it's pretty difficult to gather any objective data without doing regular engine tear-downs. If you do a search for "Regal GS catch can" you'll find a few people who use them, but any that I've read about say they catch a pretty negligible amount of oil in them, like a teaspoon between oil changes type of thing. My personal opinion is that I'd only install one if it ends up being necessitated by other modifications. The stock setup seems to run fine and have good longevity without a catch can, especially during normal driving. Once you start tuning and upping the boost levels, and/or tracking the car and potentially running at max boost for long stretches, then you might start producing enough blow-by to worry about. On a relatively stock GS I think it's a waste of time.

There are other options to making sure your intake valves get cleaned as well, like the 5th injector setup from ZZP, which adds a 5th injector upstream of the valves that will drip fuel on all of your intake valves. And as @GSTurbo said the Cobalt guys seem to prefer the Powell air/oil separators as being able to do a better job of catching blow-by and preventing the valves getting gunked. Again this to me would all be driven by some other modifications causing excessive blow-by, but if you want to do it to add an extra layer of protection / cleanliness then it doesn't really "hurt" anything. I guess to summarize:

Pros:
- catches at least some of the oil blow-by instead of having it routed into your intake and gunking valves
- can be more useful in modified setups that run at higher boost or if you spend a lot of time at WOT

Cons:
- not as effective as other methods (air/oil seperator, 5th injector, etc)
- likely won't catch much of anything on a daily driven car (unless you drive like a madman)
- can get you in trouble with the "smog cops" if you're venting to atmosphere / tampering with factory emissions equipment
- now you have to remember to keep an eye on it and empty it every once in a while

 

[stoopid]

Well said Andy. 🙂

 

[bbronner413]

I've had the ADD-W1 sitting in my basement for about a year now, still not installed (pics attached)... technically it is an air/oil separator because it has a baffle on the inside for mechanical filtration, not just an empty can with no internals.

It's been touched on by Walt G. before, but the PCV line from the Valve Cover to the Turbo is considered a non-serviceable part by GM and is a BITCH to remove (specifically the clips in fitting at the Valve Cover). This is to eliminate tampering with the PCV system, although the push-fit/o-ring fitting held by a single bolt at the Turbo doesn't have the same complications and can apparently be removed with a plastic line tool.

Attached are a slew of pictures that I've collected on the internals of the "clip" system and tools to help me tackle this some day... People on other forums have somehow used the small cut end of a zip-tie in conjunction with a small, bent flat-head screwdriver to "release" the fitting on the 4 sides (in pictures as well). I tried for about 30 minutes and had no luck but am determined to do it... Others on this forum have simply cut the line before the curve on Valve Cover fitting because of the difficulty to remove it and went that route.

I planned to mount it to the firewall with a catch-can bracket right behind my C.A.I.... run a short line from the Valve Cover to the ADD-W1, then an another line from the catch can to the turbo. If anyone has any additional insight or success with this please feel free to share! I've done about all the research I can do on it.

 

[Walt G]

And remember that the only 'external' PCV lines on this engine are the ones that flow only when the engine is under boost conditions (another reason why this makes less sense if you're not tracking the car or 'driving like a mad-man'). The path the PCV takes when the engine is under vacuum conditions (vast majority of the time on the street) is through internal passages in the head and intake manifold. It is practically impossible to put a catch can in that path.

I'm one of those with a catch can in the 'boost path', and I can confirm what was said above. I get as much out of that can after one track event (about an hour of track time) as I do in 3000 miles of non-track driving... about 1/4 cup.

In fact, this is a timely question, because I just changed my oil yesterday, and didn't empty the catch can yet. It has been about 3000 miles since my last track event, which was the last time I emptied the can. Results: about 1/4 cup (I spilled a little dumping the can into the measuring cup):


Here is my install:



Note: This is one of those super-duper cheap-o catch cans from E-bay. It sprayed oil all over the place until I sealed it up. I removed the 'oil level tube' from the side because I couldn't get it to not leak, and I had to seal up the inlet and outlet fittings with RTV, but now it doesn't spray oil all over the place.

And I went the 'road draft tube' route with mine (rubber outlet hose leads down to the front engine mount). I park my car in the same spot in my garage every day and do not have any oil drips from that tube, so cheap-o or not, it is catching oil, and doesn't seem to be letting any out the outlet hose.

I mounted mine to a little removable plastic panel on the front of the battery box, which is nice, because that panel lifts right out (with the catch can now) after removing the battery cover. There is a drain on the bottom of the can, but it's easier to remove the can from the car when emptying than trying to catch what comes out of it mounted in that location.

Since mine leads to 'dirty air', I put a check valve in the outlet hose to make sure my engine never sucks in unfiltered air when under vacuum conditions. The 'inlet' for PCV under vacuum conditions is from the rubber intake tube that connects to the turbo inlet, to the valve cover, through a check valve... didn't want my catch can to become an unfiltered inlet.

And nice pics Bbronner.. the blue collar style unlock tool is what I used to get the line off the connection at the turbo, after unbolting that little plate so I can get the hose up where I can work on it. It wasn't too bad. The connection at the engine seemed impossible to me, but ultimately, unnecessary too.

And don't forget to place the blame where it belongs: the EPA. GM wouldn't make this 'tamper resistant' if not forced to do so by law.

 

[Walt G]

I did another track day with my car last week. I had about 2500 miles of normal driving plus this track event (about an hour of running full power pretty much constantly), and got 1/2 cup of oil out of the catch can.

I think I was at the capacity of this can (again, it's just a super cheap catch can available from E-bay). I was starting to get oil out of my road draft tube, probably from sloshing/splashing in there. I got a couple of drips in my garage that night after I drove back home, and I noticed a bit of oil residue on the underside of my car near the tube outlet.

But that's another 1/2 cup of oil that didn't go back into my compressor, through the intercooler (or get stuck in the intercooler), and back over the intake valves and into my engine. I think a strong argument can be made that it's not needed if you don't track the car, but an equally strong argument can be made that you do need it if you do track the car.

 

[RIP98GTP]

Hi All, sorry I have been silent on here. With life and other hobbies I have been distracted.
I have ordered the catch can and plan on videoing the install and posting it on my youTube channel. https://www.youtube.com/user/HyperXprojects
With my schedule I don't plan on doing this until the fall (Sept or Oct 2017) There are some other things I have planed so stay tuned.

 

[BlackPearl]

Well my thing is this... Wouldn't it be better to stop even that little bit of oil from entering the turbo, intercooler and intake than to not??? And why would you Vent it to atmosphere, instead of connecting it back to where it should go???

And how would the catch can get plumbed: catch can inlet from the valve cover, and the catch can outlet back to the turbo, right???

I am soon to do this on mine to help stop whatever oil I can from coating and destroying my turbo, intercooler, intake, and fouling out my cat prematurely. So a little confirmation on this will help - especially since the air/oil separator mentioned above is basically non-existent anymore, and others are nearly impossible to figure out how the hell they are connected...

 

[Walt G]

And why would you Vent it to atmosphere, instead of connecting it back to where it should go???

I vented mine to atmosphere because I figured the catch can isn't perfect... why let any of that oil back into the turbo and through the engine? Mine is also a $15 catch can from E-bay, so I certainly don't expect perfection.

GM routed it to the turbo because the EPA demands it. I'm sure the engine designers, if they had their way, would vent it to atmosphere.

 

[RIP98GTP]

I have a 2012 [LHU] and there is only one connection from the valve cover back to the intake just before the turbo. (I looked it up in the service manual)
I can post pictures of the location if that will help - let me know.
I plan on installing a catch can I got online this fall. I need to get some tubing and find a mounting point in the engine bay for the can. The catch can I bought looks like the one that bbronner413 has posted in his post.

 

[Walt G]

There is a line that leads from the valve cover to the compressor intake pipe maybe a foot up-steam of the compressor inlet (and just down-stream of the MAF sensor)... I 'think' that's the one you are talking about. That is not the one to put a catch can in. That line has a check valve in it and only flows into the engine, not back out. That is the fresh air inlet to allow air to flow in as your PCV sucks air out under vacuum conditions.

The line you need to 'catch can' is the short braided steel line that leads from the head/valve cover area right into a fitting on the turbo compressor housing. This is the path back into the engine for blow-by when under boost conditions, and it can carry a lot of oil (especially if you track the car).

I also have the service manual, and their diagram for the PCV system is wrong, or at least very misleading. Pull that line off the intake tube and try to suck and blow into it... you can blow in, but when you try sucking on it the check valve closes.

 

[RIP98GTP]

Could you post pics please? I will have to see if I see what you are seeing.

 

[RIP98GTP]

Could you post pics please? I will have to see if I see what you are seeing.

Here is what I see...

 

[Walt G]

Here is what I see...

Your picture is perfect.

As stated elsewhere in this thread, the 'correct' one is designed to be tamper resistant to meet EPA requirements. Removing that line from the engine is probably impossible. But if you remove the entire plate where this attaches to the turbo, it is difficult, but possible, to get a line release tool in there and pop that line off. Then you can reroute it into a catch can and back to this port on the turbo, or just cap off at the turbo and route it to the ground through another check valve so you don't suck dirty air back in through this path when under vacuum conditions.

 

[dss103]

Here is what I see...

Are you sure about this? If you pull the line you say not to CC off of the intake pipe ahead of the turbo, there is oil present. This tells me it is truly the correct line to CC as it would always have vacuum to pull fumes from crankcase.

Does anyone have install pics for LHU where the line comes out of the cylinder head to the catch can? I'd like to just add a vacuum fitting after the check valve and route that to the catch can to keep from tearing up the stock equipment. Can't find the fitting anywhere and no specific pics online anywhere that I've found.

 

[Drive XR7]

How does an oil breather filter with catch valve compare to a catch can?

 

[Walt G]

I am absolutely sure that the picture is correctly labeled. If you are not sure yourself, disconnect that line from the air inlet pipe and try to blow into it (you can) and then try to suck out of it (you can't... check valve).

However, years ago I also noticed oil in that inlet pipe and figured it must be coming from that line, but it's not. After I installed my catch can on the other line, and then routed the outlet of that can to atmosphere instead of back to the turbo compressor housing, I no longer have any oil in my inlet pipe. Oil mist must come out of that line at the compressor so forcefully sometimes that it sprays back up that inlet tube. Or it's slung out there by the spinning compressor wheel.

 

[David B1]

Hi All. I have a question that I think is related to this thread, but not specifically about catch cans. I have a 2014 Regal 2.0 turbo (not a GS) with about 55K miles. I bought it used about 1.5 years ago with about 45K miles, and I don't know a lot about its history. I only daily drive the car; no track days. When I purchased the car, it used about 1 qt of oil every 2500 miles (I have been running Mobil1 5-30). This usage rate has been getting a little worse over time, and over the last 400 miles it got a lot worse (it burned through 2 quarts). That said, the car seems to be running fine - no exhaust smoke that I have noticed, no puddles of leaking oil on ground, no rough idle or other driveability issues. Seems to me that a few things could be going on. Ring or valve-train failure (hopefully not likely since car seems to be running fine?); leaking oil seal in turbo (but not seeing any oil leaks around turbo); or failed PCV system. I was thinking of starting with the PCV system. Any advice on how to tackle this? Looks to me that there are three PCV valves on the cam cover. Should I just replace them all? Anything I should look for that will help me determine whether one of more of them is clogged or otherwise not working? Is there any need for me to remove the cam cover to clean out any oil passages? Thanks to anyone who may be reading.

 

[Malo83]

Holy Shit! 😵