Air Oil Separator VS Catch Can Explained. Is One Better?

[@jamescolquhoun9636]

As a new Subaru owner, dude your channel is like the best thing ever. I had so many questions and you’ve answered like all of them in your vids already🤣appreciate it man, you a real one

[@Smeedia]

Eyyyy, glad the videos have helped!

[@justinshute5726]

Living in a cold climate and not wanting the hassle of having to keep catch can empty and hope for not freezing I went with aos. Was planning catch cans for a long time but ultimately was convinced to go with IAG and glad I did

[@Kakeyoro]

The reason why the "oil" in the catch can seems thinner is because it's not just oil, being separated. It's mixed with other vapors, including water and fuel. I would go with the Dual Catch Can system because I wouldn't want to pump anything but 100% oil back into my engine. This would prompt you to perform oil changes more frequently.

[@HandMadeRoyalty]

But doesnt the aos seperate water oil and air

[@weduhpeople8504]

Yes and since catch cans are not being recirculated with filtered oil you really have to keep an eye out on the oil level in your engine. Depending on your motor’s health or piston to wall clearance if it was done to tight tolerances or loose tolerances will dictate how much blowby you have. I noticed the oil level can drop quickly where if you weren’t checking your oil level you may find your oil level on the dip stick isn’t even meeting the minimum level required. Running e85 definitely thins the oil in your engine. On oil changes you can see how watery the oil your draining is and can smell fuel mixing in your oil which lowers the viscosity of your oil.

[@cumshot247]

Yup, on my GDI, I get this black, runny, foul smelling, fluid in my can. I surely wouldn't want this to recirculate onto the backs of my valves. 💀

[@Vermonstered]

​@@HandMadeRoyaltyNope, I honestly don't understand the point of the AOS in this configuration over a catch can. As the only tangible difference is the AOS dumps its contents back into the oil system. Adding in the complication of running coolant lines to heat up the AOS system. The coolant will be whatever your thermostat opens up the system at or generally around 180f which isn't hot enough to vaporize oil or water but will for fuel but only if given time. Being it's immediately dumped back into the oil system and you see how little actual fluid these collect (tablespoons in thousands of miles) it makes no tangible benefit to the additional plumbing and risk of extra oil and coolant lines to possibly reuse a few tablespoons of not great oil anyway.

[@spidding]

@@Vermonstered my view on this is that both catch-cans (or non-return-to-saump air-oil separators) and what are marketed as "AOS" (or return to sump air-oil separators) both have their use cases. For street/light-track applications for lazy owners - return-to-sump AOS. street/light-track applications for fastidious owners - catch can For heavy track applications with lots of blowby or if you are in a setting where you do many continuous hot laps (endurance racing etc.) - AOS. Polluting your oil mix in your sump is a lesser evil compared to running low on oil.

[@codyhendrickson7735]

IAG AOS is one of my favorite things I've installed on my car. Highly recommend their AOS, great product.

[@Smeedia]

They make a killer AOS 🔥🙏

[@cycle2bhappy]

Agreed .... the IAG is highly functional and a reasonably easy install. If I would have only removed (deleted) the sound generator tube beforehand, things would have been so much easier. Cheers.

[@Flatbushfonz]

@@Smeedia what about cobb

[@Smeedia]

Cobb is good. Just a re-branded IAG with diffrent baffling

[@peterorigenes4358]

I am installing a dual catch can in my turbo direct injected Alfa 4C. I had Mazdaspeed 3, oil catch cans were really useful that engine blew a lot of through. Like an old Porsche turbo, it you accelerated hard and closed the throttle, then nailed the throttle it was like a smoke generator. Totally normal on MS3. So was carbon build up. Some engines are prone than others. The Alfa 2.0 in the guilia has very little blow by. The 2.9 now has port and direct injection, like Fords and many new engines. Helps not only with managing combustion but also keeping valves clean.

[@Smeedia]

Duel injection is 🔥 the FRS/BRZ platforms use Toyota D4S system to prevent carbon on the valves as well 🔥

[@davidleslie949]

I was just about to say you've got 2 catch cans and one of them will be empty and the other one will have oil in it. The reason for some reason someone told you to put one on the clean side or bank one of your engine when in actuality, you only need one on the dirty side, which is bank two of your engine, because Bank one is only getting clean, filtered air through it. That's remember PCV positive crank case ventilation, so there is only one direction of flow. Your PCV valve has a check ball or check valve within it in order to eliminate any gases from going back into the engine. The other thing is never ever re-introduce any oil from a catch can or AOS. Doing so would be re-introducing small particles of fuel droplets back into your engine oil thus creating oil delusion and don't want that! Anything you catch you dump into another container to be recycled when you take your engine oil back to the auto parts store for recycling. Yeah, I think somebody just took advantage of your set up and said you would need to catch can on both sides of the engine in order to increase sales. I've never seen somebody have oil in both of their cans.. it's also a good idea to put stainless steel wool inside the catch can in order to increase the filter, media and the opportunity for the oil papers to condensate as well cool off the air, a bit more before re-entering the intake manifold. Cheers, mate.

[@zokusharuuku1091]

Aos also is a bit harder to install which will cost more. I don’t like the idea of dirty nasty watery oil going back into the engine so I prefer catch cans but my tuner was adamant that I switch to an aos with the high boost I’m running. I declined as I honestly love changing my catch can frequently so I can easily look at what’s going through my engine.

[@Smeedia]

Catch cans work great, just need to remember to drain them and they're solid 🔥😁

[@TheWestysworld]

How often do you empty it with the turbo?

[@zokusharuuku1091]

@@TheWestysworld every month or so I’ll pour out about half an inch of oil out of the can

[@spidding]

A few points to add. 1) not your fault, but I think there is a lot of misuse around catch can and AOS terms. The way I see it, a catch can is a type of Air Oil Separator. It's function is to...wait for it...to seperate the oily residue from the returned air. You can classify these generic Air Oil Separators into various types: a) a very simple non baffled non-returning unit. Still attempts to seperate air and oil but probably doesn't do a great job without baffling. (E.g. el-cheapo eBay units) b) a baffled non-returning type (like the radium units in your video) c) a baffled returning type (like the IAG/Cobb unit) 2. It really should be noted that blowby is not just air+oil. It also carries a filthy mixture of burnt and unburnt fuel. So, whilst the IAG AOS may do a good job of keeping water condensation out of the caught blowby fluid, the IAG unit is still dumping this polluted content back into your sump. This is more severe on E85 applications. Recommended to decrease oil change frequencies if they are not already frequent. This is the main reason why I have a bit of a preference towards non-draining air oil separators (aka catch cans). 3. the amount of blowby that you get (or that is caught in a catch can) is not only due to the condition of your engine. It's also influenced by how you drive the vehicle. Case in point, the catch can I run on my STi runs bone dry 99% of the time. However, out on track where oil temps can breach 120degC, this can thin the oil (I use 5w40) out to such a degree that you now see alot of blowby. I caught approx 300mL from 30min (2 sessions) of circuit driving in 30degC ambient temps. That triggered me to install an external oil cooler - now the catch can runs dry again even at track duty.

[@Dezanddavid]

Crazy I've been looking at a catch can and here you come out with a video on it. Awesome content for any wrx sti owners out there looking to mod their cars. Keep up the great work man

[@Smeedia]

Thanks my man🙏🔥😁

[@mijikle]

The idea of having an additional coolant/oil return line to rout, on top of having potential contaminated oil feed back into my oil pan is why i wont do an air/oil separator. Catch can it is. Great video.

[@Smeedia]

Loved the catch cans on this car, kept a lot of the nasty out of the motor 🔥

[@JohnNorris411]

Also, I throw a stainless steel scrub brush you use for doing dishes, into the catch can. It provides a lot of extra surface area for oil vapors to come in contact with, stick to and condensate on to drip down to the bottom of the can rather than making their way through the air stream up the exit tube to the air intake.

[@psions555]

Could you use not very densely packed steel wool like a giant crack pipe for your engine

[@BurmaJ]

@@psions555Before track days I add the steel wool and roughly an 8 ball of crack to my catch can. YMMV.

[@psions555]

@@BurmaJ Try heroin instead. It will make the motor run so we'll. Be sure to add it frequently and not let it run out or the motor will run rough

[@kwbalance108]

Though I own Mazdas, I find joy watching all of your videos!

[@Smeedia]

Ryyy appreciate the support my friend 😁🔥

[@kwbalance108]

@@Smeedia Yessir!

[@tommyboy049]

installed a catch can to my 2019 v6 challenger. kept reading, "oh you really don't need it for the v6's". Well, after 6k miles I poured out 3oz of oil

[@Smeedia]

All engines will have blow by, turbo, supercharged and high compression will have it worse but any engine will benefit from a catch can 🔥

[@lowlifeangler]

Is Challenger made by Dodge ?

[@blankfaceman9694]

@@lowlifeangler yes

[@kenmorrisproducer]

Catching .0005 ounces of oil per mile.

[@subie3138]

Nice!!! Perfect before buying!! Just My brother and I we're talking about this last week. He got the twin turbo Stinger Kia, and me My subie. AOS is the perfect fit for me 😝 Thanks for the info 👍🏽

[@Smeedia]

Definitely will help keep things healthy! Glaf the video helped 😁😁😁

[@alexudolkin2146]

The heated AOS is good at evaporating some moisture but I suspect the return oil still brings blow by fuel & water vapor back into your oil pan. 3k oil changes are crucial

[@Vermonstered]

Your coolant is only 180f, the vapor entering the can will likely be in the same range of temperature so not much benefit. The purpose of heating the AOS is to allow the water and fuel vapor to pass through because the temps are closer to their vaporization temp while oil will hopefully condense. You want the small amounts of excess water and fuel to pass back into the combustion cycle and exit the system. But for any daily driven not heavily modified car, I question why anyone would want to add an additional oil line, tap to the pan, t off a coolant line all because they're too lazy to check a catch every time they do an oil change. Or in this case it looks like he could get away with 3+ oil changes and still have few problems.

[@cycle2bhappy]

Great vid and post as usual. Just had the install of the IAG AOS done, so nice, looks fabulous in the car and functions so well. However, I did consider the catch can approach but ultimately went the "set it and forget it" route it with the AOS. Cheers.

[@SICMADE7]

This was the 1st vid I watched to learn about this and feel like I know a heck of a lot more now, thank you for being detailed! At the end of the day, I think I'll save up and go the AOS route

[@Smeedia]

Glad to hear the videos helped and an AOS is well worth it 🥳

[@xxraverxxonxtacy]

Had a Cusco on my sti and got mostly vapor, difference was running Motul 5W-40 Xcess which also helps with less blowby instead of regular 5W-30

[@Smeedia]

Interesting to know, but makes sense a higher viscosity could reduce the amount of blow by

[@s208richard8]

Motul also make STI performance oil - 5W-40 - recommended for the S207, S208 models

[@Qazxswer68]

Speak of the devil 👹 I was just explaining this to my son yesterday. This will be a great visual for him. Another one🔥

[@Smeedia]

Eyyyyyy! Perfect timing 😁

[@n7narcosis]

Cold climates - Just pour a touch of something that wont freeze into the base 10-20ml, so that it helps from freezing. I empty out once a month, and when I do I just tip a bit of RV Antifreeze in there.

[@okthen8445]

Great video. For me If it’s something like a daily a catch can is more than sufficient and actually to me better than a “AOS” because not only does a catch can not only desperate air and oils. It completely traps it in the can. That’s good because oil can potentially be contaminated by fuel and other stuff which isn’t beneficial to longevity. So yes a catch can actually is a “AOS” but it keeps that oil. On the down side you will lose oil but it’s marginal and not a concern. However if you have a catch can on a race car then that’s a different story. A race car gets wayyy more blow bye. And during a track session the last thing you need is to trap the oil in the catch can because then you’ll get oil starvation and that’s the last thing you need. So what an AOS does compared to a catch can is drain that oil back into the oil pan. Now the oil could be potentially contaminated but that’s a zero concern in a race car because the oil would be changed frequently anyways. So why not slap a AOS on a daily? Well longevity. A daily isn’t getting as much blow by as a track car and really doesn’t need to send the potentially contaminated oil back into the car. Most of the time people get an AOS because of the “set it and forget it” feature. And avoid the catch cans because they fear having to do more work to drain the cans. But you can find catch cans with drains ports that you can run under the car. That will allow you to drain the oil while you charge your oil if you will. Why not slap a catch can on a race car? Well you can but then it wouldn’t be a “catch can” it would instead be a breather tank. It’s like a catch can but with a much bigger body to hold more oil and vents the air atmosphere. So all that crap is never returning to the engine. But what about oil starvation. Well that’s where larger and baffled oil pans come into play. But that’s another story. In the end To me: catch’s cans for daily’s or even street cars (low end near stock power levels) AOS for track car/race car (high end power levels)

[@Smeedia]

I think it comes down to how you drive the car, some people drive their daily pretty aggresivly. I know toh my STI getting kn the freeway and backroads i dig into the car. Both systems function very well. And either one is better than nothing

[@okthen8445]

Smeedia your right. Driving habits are also a thing to consider as well. I always forget that because I kind of baby my sti lol and yea both are better than nothing. To be honest I got dual catch cans because it’s cheaper and it’s better than nothing even for my stock sti lol I figured out the rest after doing research AFTER installation lol

[@alexpeguero38]

Sum Guy have you noticed any oil in your catch cans given that your stock?

[@okthen8445]

Alex Peguero absolutely. There was a decent little puddle sitting in the manifold when I had the throttle body off well. There was also oil in the intercooler. I flushed it with acetone and when I drained it out the acetone was a gold color almost like brake fluid

[@alexpeguero38]

Sum Guy wow

[@HavokStrifeX]

You finally sold me on the catch can here, seeing that emptying it at oil change intervals would be fine. But hey, imagine that, 4000 miles without checking a catch can on a Subaru engine and it didn't completely overflow! Must be some pretty good engines after all! 😉

[@Smeedia]

The catch cans will definitely help 🔥🙏 and oh yes 😁

[@geriatricginger]

4000mi, and they barely had any in it? Must be nice. I put one on my 2.0T VW, and it fills up 300ml catch can in about 70 miles.. Yet compression and leak-down tests are in spec.. WTAF lol

[@clutchboi4038]

@@geriatricginger probably just means his can isn't catching as much lol

[@mrpithon]

I came from the 2004 STI series, seeing the engine bay in this car is insane. Really nice work, hope to get my '04 WRX looking this good.

[@markkenward7040]

I put a Catch can with dual vacuum lines on it, one on intake and the other to drivers side turbo. Rationale for that is that at W.O.T. or other higher throttle levels, your manifold vacuum drops off, so turbo draws on it to keep vacuum on catch can. My 2013 Ecoboost D.I. 3.5 liter can go up to 700 miles on a fill. Since I live 20 miles from gas station, I never let it get near empty . I usually check it at every other gas fill up, or about 1000 miles, sometimes less. I may get 10-12 oz. of muck which I save in garage in plastic bottle and let it separate. It does NOT use any oil between changes, and only has 53K miles on it. You get 3 distinct levels after separation. Gasoline, sludge, water. It is ugly. If you have a D.I. engine, you need one of these devices or you can pay the guys who use walnut shells to blast your intake valves. Your choice. I am thinking of buying a 2013 Lincoln MKZ sedan with 16k on it from a fellow I know, but have yet to look at it 75 miles away. 2.0 liter D.I. ecoboost. You know I will have a catch can ready for it when I get home, or soon after. Great Videos!

[@consentofthegoverned5145]

The coolant connection COOLS the vapor so it will condense out the water and volatile organics, leaving cleaner, drier air to go the to the manifold.. The gases coming out of the crank case are much hotter than the coolants system. You either want the catch can or OAS out in front of the radiator for cool airflow, or cooled by the cold output of the radiator.

[@hawkeye2816]

I've had a catch can on my turbo Veloster for probably 4 years now and I've only had to empty it once. It's not a frequent thing at all for me.

[@Sooobwuu]

Just picked up my 21’ sti and your videos are godsend. Love the work, keep it up ! ✌️

[@Smeedia]

Eyyyyy congrats on the car 🔥😁

[@billychi6961]

I have a catch can with a drain port. So I teed it into the crank breather with a check valve so pressure does not blow through the drain. I basically have an AOS for cheap it works good and drains back into the crank without the can filling up. I also capped the PCV valve and the breather into turbo inlet by the throttle body. So VC breathers from the cross pipe and crank breather feed into the inlet and the outlet goes into the turbo inlet by the power steering pump. Way simpler, way more effective and used nice fluorinated silicone stretchy vacuum hose for good seal without ever becoming brittle

[@FADWC]

I just want to say thank you for the education! I appreciate your videos my dude 🙏

[@Smeedia]

Anytime!!!

[@user-pwfus]

The main thing is the pvc system has to be a closed system with no air filter and the valve cover system has to be vented to allow air to escape when you have high pressure like rpms.

[@BuckingFeast]

My AOS cost me about $700 after shipping and duty to Canada. Took me about 8 hrs to install but definitely worth it.

[@Smeedia]

For sure, ans the first one always takes the longest 🔥

[@justinabanto8930]

Hey i know this is an old video but i just got a 2017 wrx recently and i wanted to know how did your aos handled -40 temps in canada? Im being skeptical as to getting one since im driving mine daily and its almost winter. Dont also have a garage so its always outside. Want to know if they really hold up the colder temps. Thanks!

[@BuckingFeast]

@@justinabanto8930 Not too sure I actually never winter drove mine, but I would assume it would work just fine, still get's hot under the engine bay.

[@kevinoneill41]

Keeping the octane at its best while dumping more engine sewage back into the filtered cold air to mix with the very finely metered air-fuel ratio and coating the inside diameter of the intake manifold with this sticky mixture reducing the diameter with each combustion of the cylinder. Until the diameter of the intake manifold is reduced until no air can get in. And the valves are coated with carbon. I don't get it?

[@loganramos6900]

I kinda like the idea of catch cans since from what ive seen from other research on catch cans they catch water and other junk that isnt oil and make sure its not going back in the oil, which in turn might help keep oil cleaner? Idk about that maybe not noticeable but in theory it should. Idk thats just my thoughts

[@Smeedia]

Your spot on, I just put a set of catch cans into my BRZ today

[@bradgreen987]

The IAG aos is great. I used to smell oil after a hard pull, but now nothing. Love the no maintenance. Wish I could see how much blowby is collected

[@Smeedia]

Can always swap it out for a can set up if you wanted to see how much you were getting 😁

[@DylanMorehouse]

Nice. I like how the oil is put back into the system with the AOS. Convenient. Never knew the difference and now I do! Thx bro 😎

[@Smeedia]

Anytime 🔥

[@cyberlocc]

The first can is dry, because the system doesnt work the way you think it does. The Driver side (connected to the Air Intake) is a Crank Case breather, it pulls air never pushes it. Your crank has to be under constant pressure, the PCV is to make sure pressure doesnt get too high. All the Driver side does is suck air through to push it the other side. The system flows like this. Air Intake (Fresh Air) > Crankcase breather (Driver Side) > PCV System > Intake Manifold.

[@RicondaRacing]

I never knew about the denaturing of the fuel. Getting an AOS today!

[@Smeedia]

Well worth it my friend! 🔥

[@scottdman]

Interesting video and well done. Not sure I 100% agree with all of your statements/philosophy but the video is well done and I appreciated the intro to some new brands.

[@Mike-4547]

Great video. These work great (a o s) I have seen these on diesel engines catch on fire because they were not maintained meaning cleaned and filters replaced during every oil change.

[@raybrensike42]

What collects in my catch can is a lot of water and just a little bit of oil and sometimes the can gets full of water in only a few hundred miles. I have to check it often in winter as I was making lots of short trips.

[@Smeedia]

Normal for cold climate and short trips. At least the cans are doing their job 💪

[@MrPunch09]

Wait, if its full of water then what is happening in a AOS setup?

[@wildcatz49]

@@MrPunch09 👀

[@MrPunch09]

@@wildcatz49 I think no one wants to answer this question is because we already know the water is making its way back. Makes me think a catch can is more sensible. Obviously you have to schedule you maintenance to empty the can, but they do have catch cans with an overflow.

[@wildcatz49]

@@MrPunch09 yea, I've been on other vids looking for answers. I'm going with a catch can. Just bought a zl1 camaro

[@drewthompson7457]

My vehicle engine has a built in oil separator. I added a catch can. I don't find much oil in the can, but I do get water condensation.

[@chadm6805]

It’s crazy watching this video after watching your current ones. The amount of progress and change in the sti and your channel is awesome.

[@Smeedia]

Def come a long way 🥳😁

[@joebump7034]

Question buddy Had a 2014 F-150 JLT oil separator had to empty it every other fill up with gas it definitely worked very well Just traded for 2018 F-150 purchased a brand new JLT 3.0 oil separator 3000 mi not one drop of oil so far concerned something isn't right can you tell me is this normal?

[@Smeedia]

Normal, some engines are better with engine consumption than others. So if your not seeing a ton your rings are probably seated very well

[@joebump7034]

@@Smeedia awesome thank you so much for the info if that is the case would you recommend leaving it on I have lost maybe 2 mi per gallon on my economy thank you so much

[@spaace9414]

9:18 the answer. Catch cans require draining but also the air oil separator is not made for all cars . To find a hole that leads back into the crank case matching all pressure to not throw off a code? Its very specific . I'll take the 25$ oil catch can works fine just add sum fresh oil if it's low but low oil won't kill ur car

[@Smeedia]

Very true 🙌

[@ObiWanStromboli]

Got washed away watching the differences between an AOS and catch cans and was nice to see the ol’ EJ-25 in the Bluebaru

[@Smeedia]

I low key miss the EJ 😅

[@Hyunw22]

Remember installing a IAG AOS on my sti. Absolute nightmare. Installed a catch can on my friends 86. Sooooo easy

[@Smeedia]

The 86 is so much easier to do 😅

[@davidmontano7678]

What would you recommend for a 2018 FXT that’s my daily in Colorado. Cold winters and warm summers.

[@Smeedia]

If Temps go below 0 get catch cans if they don't tend to go below 0 an AOS should be alright

[@Tea18236]

if you get a catch can rather than the aos, you can monitor the health of your engine. increased oil in your catch can may be a sign of piston ring wear

[@InGratitudeIam]

Well, that definitely clears things up.

[@MisguidedAng3L]

I just installed a oil catch can on my 2019 wrx and the turbo is noticeably way quieter, it also makes me feel like my car isn't getting the power it was before. I'm not sure if i did anything wrong or if all this is normal with a catch can. Any insight would be very appreciated! Thanks! Great content as always man keep up the good work

[@augenbutter]

The catch can on the passenger side seem to be the one needed. I just installed this one. But beware, check the hose that it comes with. Mine was a piece of junk and actually busted, causing an engine light code, due to pressure imbalance. Get a good quality, non-collapsible hose.

[@paulmarsdensr1095]

I would definitely get the IAG AOS.

[@Rah_888]

It's also to keep your throttle and intake clean

[@donovanloyer8411]

I've been advised by a very reputable local tuner/builder to not run catch cans or AOSs because with our cold weather, the tubing tends to plug up and freeze causing the crankcase to pressurize and cause other issues. What are your thoughts?

[@Smeedia]

In very cold climates it can cause any moisture in the trunk line to freeze and plug the return hole. But it needs to be very cold continuously for that

[@aaronmcilwaine3537]

Which one is better for colder weather.

[@DonzLockz]

Definitely catch can. :)

[@bradpyron8928]

Hello Sir! I know you said both Oil Catch can & Air oil separator works similar! What you suggest to work better for 2013 BMW 535i GT Twin Turbo Charge? Thanks in advance by the way I don’t care about the price at all I just want the best for the engine.

[@Smeedia]

Catch cans, will help keep some of the moisture of the oil system 🙏

[@jch2075]

In my thought process, wouldn’t the oil that you are returning back to the system with an AOS be contaminated with other substances? What are your thoughts on this possibly contaminating all of your oil? Should you just decrease the intervals between oil changes?

[@Smeedia]

Its always a possibility of pushing some contamination back through the system

[@aspenwagon04]

Wouldn't this happen regardless if you just had the stock PCV system?

[@B19D91]

@@aspenwagon04 thats what im wondering too

[@Align700nitro]

All of your oil is being containminated by the blowby from piston no matter if it went thru the pcv or not, that's why you have an engine oil filter.

[@azntuanboy]

IAG just announced couple days ago that they're releasing their V3 AOS in the fall, I'm excited can't wait great video bro!!!

[@jdmking4776]

Bruhhh. I just bought mine wtf lol

[@Smeedia]

I sae that, they will have a conversion from the V2 to the V3 avaliable also 🙏

[@janbakker9866]

What about the 100's of posts on reddit saying bad things about the aos. I have a iag aos sitting on my bench contemplating on not installing after all my research....just about to watch this video, hope it changes my mind! Love the content tho keep the solid work! 👌

[@ricardosantiago4938]

What do you think of the aos that is on top of the oil fill port? It's where you refill the oil after a oil change I have a Grimm speed

[@Smeedia]

10/10 do not recommend. Live grimmspeed but that "AOS" does more harm that good. Your better off not using on than it

[@ricardosantiago4938]

Just a question I ordered something off your site , and it said to be shipped out on the 21st , but I check usps and it says still waiting for items.jw.

[@Smeedia]

Whats the order #? I'll take a peek tonight, usps been super slow the past few days 😤

[@larryhunt1853]

Here is another benefit to running a Catch can vs an AOS: being able to monitor/measure/validate that the system is working properly. With an AOS it's fire and forget, which provides no means to monitor/measure/validate how much the system is filtering out. Being a "touchy-feely" guy, I want to know exactly what is being pulled out of the PCV system. I personally don't want to dump any of that crap back into the oil system (cause it ain't just oil!!!). Being able to monitor/record collections allows me to see changes over time, where the AOS doesn't. So I'll take the CC over the AOS and feel confident in my findings, versus only assuming. And the first 3 letters of assuming is _ _ _. 'Nuff said.

[@AlejandroPerez-cb9ub]

Tengo 3 preguntas. un oil catch can puede generar mas presion dentro del motor ?? importa el tamaño del occ con un motor L4, v6, v8 ?? y por ultimo es mejor 1 o 2 occ en un motor v6 ya que esos motores tiene 2 salidas de pcv una por el banco 1 y la otra en el banco 2 ??. Tengo un impala 2019 V6 motor es LFX y cuando le instale el occ me empezo a silbar y cuando le quitaba la varilla de aceite se le quitaba el sonido al final se lo quite todo por miedo que se me rompa el motor

[@lucienlalachance]

been waiting for this one! Good stuff err bud

[@Smeedia]

🔥😁🔥😁🔥😁🔥

[@jeffgrantIS350]

When Adding a catch can to my 007 IS350 Lexus that's both DI and port injection will I be removing the EGR Valve? I do believe that the system is under pressure and need to use a higher quality air tight can system.

[@Smeedia]

No you shouldn't need to tie into the EGR, just the PCV

[@mont7481]

I have a 2021 zl1 camaro. Thinking using a catch can. What's your opinion?

[@Smeedia]

Great option to consider, even N/A cars will still get blow by. Not sure on the C/R on the LS but higher compression will still be a victim of oil blow by.

[@roninlaw9824]

Appreciate the video. Just saw it, sold on both setups for reliability. So is an air oil separator, worthless without the coolant connections?

[@Smeedia]

Not worthless but thr coolant connections help to keep moisture from building up by keeping the AOS the same temp as the engine

[@57250tr]

I’ve been looking for a catch can for my VW 2.0 TSI engine (factory spec) and my biggest concern is freezing oil lines in winter, what should I consider to avoid that?

[@Smeedia]

For a catch can you don't need to worry about it because it will not be returning the oil. But in super cold areas an AOS can have the return line freeze if they're not using coolant to hear the AOS

[@853rudedogs2]

the catch can look handy for monitoring blow by. would be good if air/oil separator could monitor too,

[@bloodpoolxtc702]

OK so which one is the best the IAG competition or the Crawford V3 aos because im getting ready to buy one of them lol crawford is 100 less ijs!!!

[@Smeedia]

IAG has my vote, Crawford is a great AOS but practically all High HP EJs/FAe run IAG. They work great, have multiple mounting positions

[@AntonioHernandez-bp3mx]

I'm putting dual cath can on the 22 wrx would it be fine if I put em on or would there be problems I've seen someone say that the catch cans cause the blowoff valve not to work correctly

[@ericb.4358]

I installed a Cork Sport oil catch can on my 2019 MAZDA CX-5 2.5 L. turbo. At 6,000+ miles I drained 1/3 cup of nasty-looking brown liquid from the OCC. My air/oil separator would have put that crap BACK into my crankcase! Nevertheless I will have my intake valves cleaned at my dealer with BG cleaner with an induction rig. ->TIP: loosen the "dipstick" when draining your OCC to let air in and drain the can properly.

[@Smeedia]

The fluid gets pretty nasty of them, my current AOS vents everything out which helps to keep the fun luqid out

[@Rs3mocha]

i LOVE how those catch cans have a dip stick

[@Smeedia]

Makes checking them easy 🔥

[@JustinTheProCF]

I live in -30 Degrees celsius winters in Alberta and was told AOS can freeze the lines and potentially blow up. ANy suggestions for catch cans?

[@Smeedia]

Radoum catch cans would be my suggestion 🙏

[@retiredperson4054]

What filtering internal setup works the best? I have been looking hard and long for several days on end trying to discover which brand of catch can has what filter set-up on the inside and MOST IMPORTANTLY which filtering mechanism is the ULTIMATE at not only allowing oil and water vapor into the catch device but also the prevention of the oil and vapor to get pulled back into the intake. And to add to that, which device(s) may cause “restrictions” to the crankcase ventilation system - and what about the factory PVC devices do they get removed?

[@Blackntanxguy]

I see aftermarket AOS in Lexus GSF the V8 not the F Sport why is that? You can put AOS on naturally aspirated V8?

[@ImSchizoidMan]

I recall reading somewhere that AOSs have issues in cold weather, i assume due to condensation. Did i misunderstand what i read, or would catch-cans be a better option up north?

[@Smeedia]

100% spot on, in sub freezing Temps catch cans are recommended 🙏

[@boostedbuddah7784]

Looking into catch cat vs aos for my 2020wrx. My friend said everything is garbage compared to iag v3 street series but really don't wann spend 439$ for an aos. Would like to just go with catch can as long as it grabs the residual oil. I don't mind servicing. And then should I be going with single or dual? Thoughts?

[@Smeedia]

I'd suggest the Radium duel can set up, works very well/looks good and easy to service 🙏

[@5W1M]

+1 for radium dual catch cans. They’re pricey but are great. The iag aos is probably the best aos on the market. I have an iag aos v3 on my 2018 wrx rn and I’m thinking of switching to the radium dual setup since they are better than an iag aos for keeping contaminants out of the engine. On phatbotti’s website he ranks the efficiency of each and he said from best to worst at keeping contaminants out of the engine is radium catch cans, iag comp aos, then iag street aos. Only benefit to having an aos over catch cans is that they’re maintenance free. Also if you live in a cold climate, definitely get the catch cans because all aos’s suffer from sludge buildup.

[@jungleorfeed8106]

What if you have natural aspirated v8 do you need oil catch can or air oil separator?

[@Smeedia]

Catch cans would be more than sufficient 🙏

[@jungleorfeed8106]

@@Smeedia thank you very much. Great video

[@ironman1518.]

Am looking for a suggestion from you please for my 2013 Subie Crosstrek, (non-turbo), will a catch can work as well as the AOS can and save me some money? OR should I spend more on an AOS system? Thanks in advance!

[@orig6redwings124]

I wouldn't bother with either one for a non-turbo/naturally aspirated setup, unless you're making a lot more power than stock. Turbo engines produce a lot more blow-by than naturally aspirated engines do, due to the increased pressures of the turbo. In a turbo/supercharged setup, that blow-by contains oils that will coat the intake, charge pipes, and intercooler, which decreases performance. Stock, naturally aspirated engines do not have this issue..

[@giovlone742]

Finally a video on this topic, I was thinking of running the boomba cans but probably will go the iag aos

[@Smeedia]

Both are good options IMO, I'm starting to lean towards cans a little mkre over AOS after seeing the inside of that IAG.

[@giovlone742]

Smeedia if only install one catch can which one do you recommend will catch more oil on the FA20 motor?

[@Smeedia]

Thr passenger side off of thr PCV valve 🙏

[@Eric-cf8je]

I have a 17' Forester XT (the same engine FA20DIT as the WRX for the most part). It gets slightly rough idle on warm up after a few thousand miles before an oil change. I use CRC Intake Valve & Turbo Cleaner before oil changes. This seems to fix it for a while. The intake manifold sensor seems to get pretty oily. I think an Air Oil Separator would help. Thoughts? This my first Subi & turbo gas vehicle.

[@Smeedia]

Definitely would help, wouldent be pushing nearly as much oil back into the system 🔥

[@mikekillion4731]

I have the same model, did you end up getting the AOS? Any difference?

[@jonathonmcrae5671]

So, I think I've asked this before. Living up North here in Canada, we get pretty cold weather. My buddies AOS froze up on him and ended up sending oil through his turbo and intercooler. Would getting a catch can eliminate this?

[@Smeedia]

Catch can would be better imo for very cold climates

[@jonathonmcrae5671]

@@Smeedia Mind you during the summer we get normal hot weather. It's just in the winter we get closer to the -25c weather so.

[@jonathonmcrae5671]

@@Smeedia Also, would the Boomba catch can suffice?

[@ryanarch7366]

Great video as always! What was your reasoning for going AOS on the blubaru and dual catch cans on the BRZ and not both AOS or both catch cans? Wanted to try each out?

[@Smeedia]

Wanted to be able to compare the two as both cars are driven. Personally I have no prefrence on either option. Theyrr both good to have but catch cans will typically always be cheaper

[@tdro98]

On a ej205 Will you get more oil from crank/pcv or from the heads?

[@kroviken]

Great explanation friend! Thank you! - from Subaru driver Malaysia

[@Smeedia]

❤❤❤

[@hitom43]

Can you add a catchcan between the engine and the pcv? How would it affect the engine?

[@Smeedia]

Technically speaking yes you can it would essentially just be an AOS

[@future_phonk]

I think catch cans will be better for people who want to monitor engine extremely closely by measuring how much oil blow-by every X amount of miles or engine run time.

[@Smeedia]

Another solid reason for cans 🔥 I use a large catch can on my STI now

[@future_phonk]

@@Smeedia I was watching motoiq video on catch cans but if you intend to track a car, apparently catch cans can fill up pretty quickly.

[@michaelhernandez1398]

I got the IAG AOS and want the radium setup now because I can’t actually see the oil getting caught lol I’m paranoid it’s not doing it’s job

[@luxurygeneration407]

What if it is not turbo can you still run still run two catch cans. My car is a Hyundai.

[@Smeedia]

You can but it's over kill, 🙏

[@carlnewstrand9408]

Great information. But what about diesel engines. I have not heard of catch cans with diesels. They have much higher compression than gasoline engines. Thanks.

[@gregnixon1296]

What kind of hose is necessary for catch can back to intake? The 3/4" heater hose that I used collapses. Heat from the engine makes the hose pliable, and the intake's vacuum pressure causes it to collapse.

[@Smeedia]

I used a reinforced PCV hose that I bought from O Riley's has not given me any trouble yet 🙏

[@17.06.Copper]

Hi Smeedia, I have 2016 Forester 2.5i FB25 block and decided to run a catch can as I had my original block after 200,000km, succumbed to an internal head gasket leak. Rather to repair it, I opted for a low KM 2017 FB25 block and had it recently installed. I'm trying to get as much longevity as possibly and thought the oil catch can would help. I have heard that it also increases crankcase pressure and acts as a restrictor to the PCV system. Have you heard of this and do you have any insight for me?

[@MR-oy4fc]

I run the dual catch can setup from Radium in my STI. I like them better than the AOS I had that always wanted to leak coolant.

[@Smeedia]

I had one of my IAG ones do the same 🙃

[@TheShadeManGuitar]

Gunna throw one on my 06 gxp. Seen i was blowing blue smoke on decel and start up. Pulled the valve cover to see a gummed up pcv baffle. Gunna put a catch can as precaution as I drilled out the valve cover baffle so it would not clog again

[@Smeedia]

Not a bad idea, hopefully helps to clear up the issue 🙌

[@robvanhalen9696]

So, you recommend this for every WRX, but Subaru tells me installing one will void my warranty. I have a brand new 2020 WRX with only 4000 kms on it. Should I wait?

[@Smeedia]

Unfortunately it will void it, but it is something I suggest doing qhen your outside of warranty

[@JohnNorris411]

old video so late comment but I would have taken the can from the driver's side and attached it to the passenger side downstream of the can that is catching oil, just as a test to see how much the second can would catch in comparison, to get an idea how much oil vapor makes it past the first catch can. I am curious just how much oil the can is actually catching? 80%, 10% or less? how would you even know unless you are some how able to catch 100% of the vapor before the intake then do the math on what a single catch can gets.

[@duckboy01]

Are AOS's legal in CA? My 2014 FXT is due for a smog check soon.

[@Smeedia]

I know some are CARB legal but not sure on which one is

[@garyvanremortel5218]

Don't put fuel diluted oil blowby back into your sump. A catch can is better IMO. AOS is for people too lazy to drain a catch can. Place it in a hot area of your engine bay to ensure water and fuel are driven off and all you drain is oil. This is basic physics. Having a catch can or AOS is even more important if your engine is direct injected.

[@jdmking4776]

Ooooo EG33. Love that engine.

[@Smeedia]

Yesssss 😁😁😁

[@jasonjones2871]

I opted to go with the ADD W1 catch can and only installed the CCV side (passenger side) as I've seen so many videos regarding duel cans that have the same results, dry PCV (driver side) can. The product is comparable to many others but at a lower cost, $170. Haven't seen too many WRX/STI's with this brand, have you heard anything about them?

[@Smeedia]

Can't say I have, but I do agree a single catch can is really all that is needed

[@mattm920]

Do either of these void warranty? Also, in the winter months of Chicago is one better than the other with cold temperatures.

[@Smeedia]

Both will void it, and catch cans will be better for colder weather 🙏 an AOS return line and freeze due to potential moisture