A lot of questions asking "why don't catch cans come stock on cars?" Lots of reasons here, but some of the most obvious: 1) It's another maintenance item, and customers have a hard enough time just keeping up with oil changes. Examples like AdBlue and water injection systems, come to mind, engineers try to develop solutions around customer maintenance. 2) If a customer neglects it, the catch can fills, and then you're dumping that oil into your intake; this is worse than doing nothing at all. Then it's a liability issue for the manufacturer. 3) Ideally, a proper engineering solution to prevent carbon buildups wouldn't require any effort on the customer's part. This is where auto companies will put their focus. "How do we prevent carbon deposits." There are companies that do much better than others with DI engines. Catch cans are not the only solution. If you have an engine that suffers from carbon deposit problems, a catch can is likely to improve the system, as demonstrated in the video.

Pffft...all filters do is weigh your car down and keep you from buying useful upgrades like wheel spacers and carbon fiber gas caps.

Are you getting one for your Tesla?

I made an oil catch can for my antique Chevy S10. I purchased a 32 oz Ozark trail thermos from Walmart for 9.99 and I drilled two holes in it, one a couple inches up from the bottom and another a couple inches down from the top. It took a lot of effort, but I made a stainless steel baffle slightly above the lower hole. It was interesting fitting that piece inside and epoxying it in place, but it works quite well. As far as a filter, I purchased a 3-pack of coarse stainless steel scrubbers from the dollar store and put one inside the thermos, just above the baffle. A line from the PCV valve goes to the bottom hole and the return line at the top goes to the throttle body. I'm fortunate that there's plenty of room for this larger than normal catch can. I wanted a large can to make it easier for the moisture and oil to settle out. With the stainless steel scrubber in there, any vapors have to pass through the stainless steel mesh. No need for any other fancy filtering. The engine has 288 thousand miles on it. I was having some severe moisture issues which I thought was a head gasket leak. It turned out to be my thermostat running 15° to cool, a much colder than normal winter weather, and the largest item was the oil filler tube o-ring was not functioning because it had hardened up over time. This allowed cool damp air to go directly from the oil filler tube to the PCV valve. Since it wasn't sucking air through the vent tube on the opposing rocker cover, there wasn't much circulation. The moisture was building up inside the engine and up into the vent tube. Once I sealed up that O-ring on the oil fill tube, my moisture issues went away because my PCV and the vent tube were operating as they were supposed to. Initially I had to catch can on the vent side of the engine were all my moisture issues were showing themselves. After installing the O-ring the catch can have absolutely no residue in.... Nothing. Because of that, I switched it over to the rocker arm with the PCV valve. The catch can is collecting oil only. No water vapor whatsoever. The other thing which surprised me was once I sealed up the O-ring and the PCV system was operating correctly, oil leaks from my engine virtually ceased with the exception of a tiny amount from the rear main. If you have engine oil leaks, be sure to check your PCV system and make sure everything is operating correctly. A minuscule amount of vacuum from the PCV system can keep pressure buildup from forcing oil out of the timing cover and rear main seals. My engine is unbelievably dry now. Over the years I rebuilt two engines, ported a brand new set of heads and installed larger exhaust valves and I've done all of my own automotive work for 50 years. Unbelievable that I just now understand the operation of PCV system. 😞 The journey and the discovery of my problem is all because I googled oil catch cans. I thought they were only for race cars. Nope, they need to be on every car.

Well done, Jason. Several comments if i may. 1. Can a car owner check whether he really needs an oil catch can? I think he can. Simply by disconnecting both vent lines (most engines will have two such lines) where they enter the intake system, one can then use a cotton swab to wipe the insides of each pipe or hose. If the swab comes out wet with oil you will know that oil and other stuff are passing into the engine intake system, and a catch can will be a good idea. If the swabs come out perfectly dry then not much oil is getting back to the intake and no catch can is likely needed. 2. I suspect many car manufacturers are doing a better job today compared to ten years back of reducing oil and other stuff from venting back into the intake systems on their engines. Why? To enable the combustion process to be as efficient as possible and to reduce those wicked intake valve deposits. They are doing this by placing the features found in the better designed oil catch cans into their PCV systems to do the catch can job. My example: We have a Mazda CX-5 Turbo (gas direct injected). Though the PCV hoses were dry by the swab test, I put a catch can on the engine anyway. All it gathered was light amber-colored clear water. No oil floated on top of this liquid. Though I am sure a little oil was in this mix, I felt it was too little to make it of any consequence, and I removed the catch can. I believe the very canny (bad pun) Mazda engineers included in the engine's vent system an oil separator to capture that evil (in this case) oil and drain it back to the crankcase. We also have a 2018 Charger 6.4L Hemi. It is not direct injected. Nonetheless I have a catch can on that engine, and it does collect a small amount of fluid which contains some oil. I am quite confident, however, that when I put my right foot down the port injectors liberally wash those huge intake valves and, thus, deposits will never be a problem. I always enjoy your videos. Keep up the good work.

How much oil can an oil catch can catch if an oil catch can can catch oil?

My srt4 came with a factory catch can. It was the intercooler 😂

I've has the $25 one on my car for about a year and a half and have not been disappointed!

I recently installed the $25 can (by Evil Engineering sold on Amazon) on my new ‘22 Hyundai Veloster N. It came with a nice aluminum mounting bracket, two different sizes of screw in hose adapters, and some steel wool padding to use under the little baffle in the lid. This helps catch more oil than just the baffle itself. Also- I found out the dip stick screws into the bottom of its cap, and can vibrate loose in time, allowing the dip stick to fall into the can. I unscrewed the dip stick from its cap, and screwed it back together with a dab of loctite. Great video Jason! Thanx!

"All of my cars are either port injected, or they run on electrons or something" ahahaha

I didn't know that I needed one of these. Fun fact: I actually really love maintaining equipment. I don't know why. There's just something super satisfying about restoring things to peak condition and keeping them there, especially with more and more things to take care of.

I installed a baffled catch can a month ago on my 1998 Ford (Mercury) Cougar 2.5 V6 with 52,000 miles. Engine is in very good order apart from a couple of vacuum leaks which are being rectified. I only do around 3000 miles a year in it, and so far the catch can has stopped around 5ml of carried-over oil passing through the inlet. I have disabled and blanked the EGR valve which prevents soot and carbon from further clogging the intake, especially when it blends with the oil vapour from the crankcase breather. My can is identical to the $100 product on this video.....in the UK I paid around £20 for it and I am very pleased with it.

For anyone interested in modifying a car, and considering a catch can, this is an absolutely awesome video. Also, big thanks for featuring the Humble Mechanic, yet another awesome KZfaqr that I can subscribe to for more knowledge! (I'm seriously starting to overload on good information thanks to so many excellent KZfaq channels.)

Always fun to help out Jason..

They absolutely work. I just fitted one to my high mileage NA car yesterday. The difference is night and day. Oil was pooling in the intake manifold and the engine was pinging slightly at most mild load conditions. The engine was being fed oil mist, effectively lowering the octane of the fuel. The pinging is now gone completely!

Ah finally, i've been trying to decide how to route a catch can on my high mileage N/A car. Nobody else mentions the PCV valve but you. Couldn't see the logic in routing it from both rocker covers when that pcv valve is going to intake! Cheers.

Jason thanks for the awesome channel. Being an electrical & robotics engineer myself I appreciate your level of detail and data behind your content!

Glad that my BMW V8 already had an oil/air separator 20 years ago... But it's also BMW, so in order to change it I need to remove the timing chain😆

I used a catch can in my 2005 350Z. The VQ35DE RevUp was notorious for burning oil. After I swapped the engine for an LS3 back in 2018, using the same catch can, I still haven't seen any oil getting collected. The LS3 has been a superb engine and a great upgrade for the money!

2:33 "Now with port fuel injection on my S2000....." Auto-subtitles: "Now with port fuel injection on my ass mm" 0_o

I had a $30 install on a sonata turbo and I was amazed how much mixture was in there, easy to drain just unscrew and dump. No filter on it but a scotchbright did an excellent job. Those $200 plus are just names you're paying for.

A caution on using oil catch cans in winter: don't. Condensation increases, more water collects in the can and then freezes. This requires close monitoring to drain the can when it's hot, otherwise water will build up to a level where, when frozen, it will interfere with airflow in the PVC line. PVC pressure goes up and bad things happen.

Used one on my semi, got 1.5M miles before in frame. Also using oil tests was able to extend oil drains by about 50%.

I happen to be using the cheapest option shown here, I bought mine prior to finding this video. I have a 2.0 GDI non-turbo motor in my KIA and have been very impressed with how much condensation it catches.

FYI: Inside the $25 OCC, you can unscrew the "baffle" under the lid so you can install different filters to suit your needs. Foam works well too.

A lot of people are asking why the manufacturers aren't including these on new cars. They don't want to advertise another maintenance item that people need to do, and don't want the liability. If they are never emptied, that can be worse than just not having one. Let's say your can is completely full, and then you drive on some sort of slope, a huge (yuge!) glob of crud is going to get sucked straight into the valves and pistons, and that's bad. Kudos to every DIY'er who takes care of his/her car. 97% of the people buying cars would say, "Huh?"

Just discovered this Oil Catch Can and I'm considering for my 1.0 TSI Volkswagen here in Brazil 🇧🇷 Thank you brother ♡

man your videos are getting better every time. Good job. I inspire how I make my videos in some of the good KZfaqrs automotive related and you are one. Good job and thanks for the video

These are some of the best car vids on KZfaq. Thank You!

Back in the good old days, engines had something called a "road draft tube" which just vented pressure from the crankcase to the atmosphere. No oil in the intake manifold or on the valves, no reservoir full of dirty oil sloshing around, no problem. Goddamn you, EPA.

Great video explaining oil catch cans. My Alfa Spiders came stock with oil catch cans. They use a metal mesh membrane and the swirling motion drops the oil to the bottom of the can. There's a oil return hose at the bottom of the can. What great technology in an car designed in the mid 60's!

Finally someone with actual scientific research to back this up, thank you!

Thank you I finally have learned what the catch can actually does and how effective it can be.

After I owned my 2015 Fusion with the 1.5 Ecoboost. I put like 10-20,000miles on it by the time I put a catch can on it. I was ignorant to direct injection with a turbo. Then it fell under the coolant guzzling as it was dumping coolant into cylinder 1. I was able to trade out and up to a 2017 Fusion Sport. I got it with 42,000 on the clock, first mod was a catch can. Been on there for 9,000 miles now. I'm trying to preserve this car the best I can and keep miles low. They only made this model for 3 years. And many have been wrecked already.

I have a naturally aspirated 3.0 l6 and installed an occ recently. The engine already has a cyclone oil separator part of the valve cover. The occ catches insignificant amounts of oil during summer days. During cold days the same plus a good amount of water. In the winter there is a risk of water freezing and destroying the can. Also that water may have some cleaning properties but probably not, probably it’s condensation from humid air not water droplets and humid air doesn’t clean anything. There is an yellowish oil-water mixture that covers the walls of the tubes. This mixture gets into the manifold slowly and could affect parts of the manifold. For example mine has flaps to optimize manifold airflow and oil can affect them, but I doubt it can be stopped completely.

A tuned Pontiac Solcetice with 800K KM?’! Stop lool! That’s impressive.

Good explanation of a real problem. Auto manufacturers don't want engines to last. People who think otherwise have no idea how much acidic water and contaminants are being recycled through their engine.

I have the Mishimoto compact unit; its filtration is excellent and on my turbocharged 1.6 MX-5 it fills up with mostly a watery, fuely substance in about 3000 kilometers. This is mostly beating on the engine very hard, so all in all even its small size isn't really a problem if you're already involved in keeping your modified vehicle in good operation conditions, which would imply you do general checks and minor maintenance around/before that interval anyway.

I put a cheapy ($30) made for a BMW because of the 3/4" port size on the 4.7 in my 04 Jeep Grand Cherokee. Going on 3 years now, living in a northern cold state it really fills up with condensation water in the winter and just a bit of oil in the summer. I can say with it and PCV system I modified to the match the later 4.7's the oil cap is now completely clean and dry on the bottom. Used to get a milky coating in the winter from all the moisture that I now catch with the can.

Oil Catch Can: *exists USA: *Heavy breathing

for my civic i like to use a fiji water bottle as a catch can to pretend i have money

Put one on my 2.7 ecoboost and I have definitely been happy and it's showing was needed. Especially in the winter time catches a lot more.

I'd like to see a more technical follow up to cover the recent AOS that integrate engine coolant passages as opposed to old school catch cans. Like the AIG AOS for the late model WRX/STi

I have the smaller can with the bronze filter on my 4WD 2.5 turbo diesel. It's a Mitsubishi Triton here in Australia. It's plenty big enough as I check it every 6 weeks roughly and it only has about 1-2 teaspoons of oil in it. Got it on ebay for 26 bucks delivered. Exactly the same as the one in this video.

Little trick. The old Lexus 2.5 V6 engine you will find on the 2IS is known for it's carbon deposit. Catchcans are basically a must have for those cars.

Something people forget with oil blowby is it can massively reduce octane, so those of you pushing it with timing or boost should consider it a must.

Great video. You forgot one important detail. The PCV system not only releives pressure inside the crankcase from blow by, but it also removes the fuel vapors from the blow by. The PCV system removes air/fuel mist from building up inside the crankcase - which is dangerous. So it's not just oil mist that goes to the intake manifold, it is fuel mist as well.

One of these was vital for my old srt4

isn't any VW enthusiast a mechanic by default. how else would they get from A to B without a tow truck.

I love Chuck's vidyas. Great video, Jason and very informative.

Thanks for answering the title in the first 8 seconds of the video!

Jason, I think it would be interesting to see the difference between a regular GDI engine, a internal "catch can" system and a dry sump "breather" system. The new generation LT1 Corvette/Camaro have these differences. Even the 2017+ Corvettes use a different PCV routing system than the 2014-2016 ones.

I bought the $25 one and added a sintered bronze filter and a drain plug and hose. Works fantastic.

Very nicely put together video and very entertaining as well. Thanks for posting this.

Who knew that I'd get to see ZZ Top in your video.

8:26 I have this $25 one on my Forester and added 1.5" of stainless steel wool in bottom. I had to buy fuel line hose to replace the flimsy included hose. Now it works like a champ!

The bronze filter got clogged up on my one and the pressure building up in the engine (BMW 325I N53) made the valve cover gasket leaking. I took the bronze filter out and placed stainless steel wool in the catch can. Works now even better.

Provent 200 works great, has a drain, flows more than most pcv will ever flow, has replaceable element, drawback is size. I have one on my old Mercedes 300D turbo. The blow by is redirected and instead of a oily mist going into the engine it's nice and clean now. In this case there is a lot of blow by and would drip oil from the connector to the turbo before I installed the provent.

Man, I love your videos... Always very informative!

You should do one on air oil separators and then go into advantages and disadvantages between a catch can and an aos

Guys, I love this video. Thank you so much for your time and expertise.

Damn dude, you really stepped up the videos!

You are really good at explaining things very well 👍

Very useful and informative! Thank you

Oil air separators on the PCV system are actually very helpful especially in positive manifold pressure designs. The intake Scavenging that OEM happened to go after reroute oil Vapor back through the intake. Severy et al military tests showed oil vapors ignite a full 100c colder than gasoline. Oil Vapors back through the engine is technically asking for detonation/preignition if enough of it is there

I have the 25 dollar one and it came with a stainless steel pot scrubber ball that baffled the oil in the can and keeps it from sloshing. Works Brilliantly

I’ve looked at the cheapest option he has here and they do have the ability to filter the part with the baffles unscrews and you are supposed to place steel wool in there to act as a filter

you could expand on this topic by talking about PCV vacuum pumps which directly increase HP output , & or the lesser approved of method of running a line from each valve cover into the exhaust header collector at a 45 degree angle and cap off the hole in the intake all together.

Interesting video to be sure---thanks for your time creating and sharing this with us. I found this after reading such a device could reduce deposits even on PFI engines like my Ford 5.4 normally aspirated. I would think draining one of these during each oil change would not be a huge issue and would prevent them becoming too full. Thanks again!

Very interesting, I have read for years that the Gen III Chrysler Hemi tends to build up deposits behind the throttle plate and catch cans are recommended. I have not installed one but have used Mobil 1 since I bought it (when it was 2 years old 25,000 miles) and when I checked it recently it was pretty clean. Our other vehicles with port fuel injection haven't had obvious issues with build up on the throttle plate or valves (98 Subaru, ran it to 186,000, 98 Jeep, ran to 181,000, 17 Jeep, now at 78,000, 17 Subaru now at 60,000). However we used to own an '88 Toyota Camry 4 cyl and an '89 Toyota Corolla GTS with the 4AGE engine. Both, would develop deposits on the throttle plate to the point that the gas pedal would get stuck with a cold engine. I had to clean each one yearly. Not sure why this was, but it was consistent problem. These might have benefitted from an oil catch can but they weren't common then. I do miss that little 4AGE engine though, it was a fun car with the 5 speed.

You can look at the outlet to see if oil still stick to the walls of the hose. Those with fine filters will probably create resistance and high cranckcase pressure which can blow various gaskets. Also the inner diameter of the hose should be very close or larger than the original I’ m installing a cleaning injector on my gdi, the project is almost ready. Waiting for the pressure sensor, T low pressure line adaptor and some programing of the control box

Nice video , you forgot to mention the effect oil vapor has on knock threshold. High performance engines use catch cans ; or just vent it to the atmosphere; to try to keep the oil out of the intake . Oil has a very low octane rating so it wouldn't take a whole lot of oil vapor to lower the octane rating of the fuel you are burning in the combustion chamber and lowering your knock threshold.

Great timing! Just bought a 2019 GTI and was looking for oil separator info.

Excellent Video, a bit long, but very detailed and a very worthy watch. If anyone does not have a catch with GDI, they should do it immediately!! As an engineer, you are Spot-On here! Very Well Done, Thank You

You’re awesome. Totally appreciate your video content. Love the science of automobiles!

I have been wondering what those actually did for years now. Thank you for letting me know. I'll get one for a newer car that has direct fuel injection.

So he talks pretty quick and efficiently already... I forgot it was still on 1.25x playback. My eyes were popped out of my face trying to keep my brain up to speed with his words 🤣🤣🤣 great information

Absolutely a must for BMW e46. If you attach the catch can input to the drain on the dipstick tube it the can can be hidden under the intake tube yet still simple to access for maintenance.

As always am great information wonderful way of delivery .. but with that awesome team work and editing .. man am a subscriber!!

Great video. Just run a 3/8 hose from valve cover to bottom of the car. Install a piece of screen at the end. Cost $2.00. Illegal? Who cares. Just put the original hose back on before emission test.

A better solution would be to have some kind of filter or deflector inside the crankcase, before the PCV valve. The collected oil would just drop back into the case. Actually, some kind of retrofit plug would be feasible.

I like that Idea. You had a motorcycle case on your desk so I thought that you would talk about the cans use on MC engines.

You should do a video on HHO generators and prove that you don't get an increase in fuel economy nor power. Your scientific methods and explanation is second to none!! Another great video, thank you!

I was planning to get a catch can, after finding pools of oil in my manifold, now i will be getting one... 👍

Oil catch cans definitely do their job well. I purchased one several years ago for my Camaro and it filters out about 1/4 cup of oil per month. Good video.

Good info and thumbs up for using the metric system.

Just a note for carbed engines; the old Triumph motorcycle manuals used to say to drop the throttle just before going wide open, because that would suck a "certain amount" of oil to the rings. Of course, they had looser tolerances and like Harleys, were SUPPOSED TO burn a little oil between changes!

The best design is the $25 one with two Scotch-Brite pads (stainless) inside. They cost $2 and fit perfectly. This setup has caught lots of oil in my '04 Wrangler.

Seeing that you used to own a Subaru, would you do an oil catch can vs AOS (Like perrin or grimspeed)? Your in depth videos are what brings me back and I'd like to see someone who knows the science to shed light on this topic.

Some steel wool in the 25$ one makes it the best bang for your buck. Just put one on my car, after 2.1k miles I checked it and it works perfectly.

Best location for an oil catch can I would be curious to knowing. You've answered my other questions about it in the video

I actually have the $25 catch can. The baffle unscrews from the top and apart. It should come with a 3M 84CC Scotch-Brite pad that you rip off and put inside and reassemble. You do have to change it though. But still worth the $25. Easy install and saves you in the long run.

IAG makes a really nice catch can for Subaru's, it has coolant running through it to keep the fluid from freezing

One question I have never seen an answer of elsewhere is - How Long is Too Long, for the In/Out Hoses? My goal is to place the CatchCan down in front of the Radiator, to get Can as Cold as possible for Condensation. To achieve that I would need to run a 3m Cl. ean and a 3m Dirty line hoses (as I want to keep the engine bay 'Neat' & Least Intrusive to the Mechanics when doing Scheduled Servicings. I see the 3+3m of Hose results in quite a High Resistance to overall PCV AirFlow... (as tested by using Lungs to Test Blow the entire hose/can/hose setup)

Loved the video was hoping you were going to show how to install it.

Go to 2:34. Turn on subtitles. Thank me later

I installed a catch can on my prius 3rd gen years ago and i'm glad I did. The prius has a lot of blow by.

Great video Clear and very informative You did an awesome job

Fantastic video. Thank you for explaining things

Having not installed one of those cans on my 1990 Hyundai Elantra has caused my headlight fluid levels to fluctuate erratically and my discombobulator to quit working. I sprayed some WD40 on the windshield wipers and it kinda helped for about 2k miles. It also added about 20 more MPG to the car.