What Is An Oil Catch Can?

[@gaborbata8588]

Nice, clear explanation. I'd add a few extras for those curious. Historically, crankcases were ventilated to the open air: dripping to the ground, that is. It's environmental thinking that had lead to feeding it back to the intake. (Some engines still have the open tube, like older style lawnmovers.) Stock engines also have some sort of separator already built in, that allows oil to condensate and drip back into the head or sump, before drawn in by the intake. It's not only the leakage of piston rings that causes crankcase pressure, you also need some ventilation because of the obvious reason of thermal expansion in there, and the movement of the piston(s) themselves. (Interestingly, the latter is what's actually utilized in two-strokes, this pressure is intentionally contained there.) Speaking of the crankcase gasses, it actually contains a large amount of water vapor. What you can see as gunk in a ventilation system is a tiny amount of oil residue building up over several years. In our workshop we've built and tested condensation type cans on a carburettor engine and on an injection one also. It extracted half a litre lightbrownish water quite quickly, so draining the can was really needed. You can still have the benefits of a filter-type can, though, like shown here, as these catch oil particles but let water vapor pass through, as far as I can tell. All in all, since most of the oil can be separated (done in the valve cover most often) and water vapor is not harmful, it's considered safe and not having major drawbacks feeding it back to the intake. I just hate the look of oil in my engines' intake parts myself :)

[@youseftawhed]

Quick question, my front seal on the crankshaft leaked oil after 400 miles on my brand new ZL1 after the dealership replaced the seal, a buddy of mine recommend to insta that catch to insure that the pressure won't build up again causing the new seal to pop again during speeding or track use. Do you agree that the catch can would help with that issue?

[@gaborbata8588]

@@youseftawhed Your crankcase shouldn't develop that much pressure to begin with. It typically occurs in old engines with worn-out piston seals and bores. The pressure won't drop with the can installed, unless you disconnect it from the air-intake, and let it breathe openly.

[@428ghost]

CAUTION FOR COLD CLIMATES: disconnect your PCV catch can in the winter. Condensation in cold climates results in a lot of water building up with the sludge in your catch can. The result is the requirement of having to drain the catch can with increased frequency due to fluid build up. In extreme cold (-20C and below) the engine will have to run for quite awhile before the ice inside the catch can melts before you can drain it. A risk with an oil catch can in winter is that ice builds up to the point where there's a blockage in either the can or the line to the can. The result is PCV pressure builds up in the crank case and very bad things can happen to your engine. I've had my valve covers rupture one winter on a -30 C day due to a frozen catch can. You've been warned: not for winter use.

[@ArturKala]

Oil catch can can catch oil.

[@drb2k]

ArturKala it's a palindrome.

[@theq4602]

racecar

[@BillCut]

a toyota

[@sctm81]

radar

[@halffastmiata4781]

Never odd or even

[@daviddavid4962]

This is the BEST explanation I've heard. Some guys talk such nonsense but you have made it so simple to understand - thanks bro.

[@15DurangoRT]

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

[@Malaysian08H]

HDscreenerX 🤣

[@BrotherWitch]

An oil catch can can catch as much as oil as you can change consistently. Can you keep up with continuously collecting caught castoff collected in an oil catch can?

[@louisyeo2009]

Oil catch can could catch oil if the oil could be catch by oil catch can. However if blowby pressure is too high even an oil catch can could not catch the oil, oil leaks into the air intake damaging your intercooler, turbo charger, intake manifold etc..

[@BuddyRHS1965]

Thats why its good to change $5 pcv valve with every oil change ??? Once a year?

[@amonmcranny2654]

I think you meant to say "How much oil can an oil catch can catch if an oil catch can can catch oil"

[@Deathnote0-_-0]

haha, the best thing I heard: "People are lazy.... Remembering to change your oil is challenging enough."

[@EverydayLayman]

I laughed at that too!

[@mattslaviner1867]

Hey some of us work 6 days a week!

[@Ac18Korael]

It's only twice a year you have to do it haha or 6000km ( depend of the brand )

[@RzVids]

Matt Slaviner really like 5 minutes to dump the oil that’s it.

[@kiyoponnn]

@@RzVids Agreed, you'd be a moron not to do it yourself

[@roymaron7240]

Your videos are absolutely amazing!! the explanation is clear and simple enough that someone that has an interest but no background knowledge can still understand them. Makes me happy to see an engineering channel with nearly a million views, good luck and keep going.

[@madfiat8932]

Especially important if you have either Direct Injection or Turbo engines, especially if your engine is both. Direct Injection you don't get the cleaning action of fuel on the intake valves, so that oil buildup becomes a serious problem. Turbo has higher pressure and thus more blowby under boost than a non-turbo, and thus more oil consumed through the PCV system. One caveat also, if you have a turbo engine, you have to make sure the PCV valve itself stays on the correct side of the catch can as you don't want boost going into your catch can!

[@vdub5818]

exactly. The fiance has a optima with their 2.0T GDI. Catch vans are a must for that car same with the 335i BMW's. The intake valves start looking really bad when you pack on some miles, and it doesnt take much carbon buildup at all to kill power

[@MTreddevil12]

that's why some people just remove the pcv altogether. Just another area for boost leaks so you either use a catch can to atmosphere or back to the intake pre turbo.

[@jmarriottc]

Exactly, I have a catch can on my Ecoboost F150

[@madfiat8932]

Macus Thomas On some cars if you do that however, you will trip engine codes and reduced performance from the ECU. Keeping the EVAP and PCV sensors happy is a big concern on newer cars.

[@MTreddevil12]

Hence why I don't own anything new lol

[@MrCROBosanceros]

First time ever,I heard about that.I'm lazy person for anything but,my car and my job.I'm always looking for any tip on prolonging life of my car.I don't care much for performance.Almost any new car has more performance then we need.Thanks for video!

[@EngineeringExplained]

I like your approach to performance haha, and I'd tend to agree. Cars are crazy powerful these days!

[@SmewthePew]

Than

[@MrCROBosanceros]

You right,cars these days are heavy.But talking about petrol head?I'm 52 years old fart and the bus driver.When you drive 40 footer bus,full of people,and many,many of those are geezers,you are obsessed with a smooth driving.I just like when any machine works properly and efficiently.,All that rubber burning that you see on TV all the time,to me is plain perversions.What is a purpose of that?

[@howardmarburger515]

I watched 10 minutes of another guy's 17 minute video on the same subject and you said everything he did in your first 90 seconds. Keep up the great work!

[@mosesberkowitz3298]

Very Good topic and video! Wish you had mentioned a couple cars that have catch cans as an example. My favorite part is your drawing....don't change it to some computer generated diagram....the fact that it's homemade makes it memorable. Good Job !!

[@amirHoe]

He said one thing i already know... people are lazy.

[@ricepony33]

I completely understand why you make short videos for consumption, however it would be great if you had either a second video or channel that went more in depth and you could link to that for those of us who wanted more content. Just a thought, great channel.

[@xXDarkice]

Yeah I agree I'd watch two ads for your content for sure.

[@EngineeringExplained]

What did you want to know about catch cans that you didn't get from the video? Thanks!

[@ricepony33]

+Engineering Explained I was speaking more generally about the tech focused segments. On the catch cans maybe discuss the different types, sealed vs atmospheric, baffle design, eBay vs high end etc...

[@abadmixtape]

Here's my review of an eBay catch can... don't buy it

[@xXDarkice]

Engineering Explained I was thinking more of the science behind it.

[@428ghost]

I have one. It's a bit of a hassle in winter though. Condensation builds up due to the colder temperature and freezes inside the can. If you don't drain it enough when the engine has heated up, the frozen water can block the hoses and allow the blow by gases to build up in the crankcase anyway.

[@mykill1221]

"Remembering to change their oil is challenge enough" hahaha

[@bandroid404]

Visiting the Volkswagen Autostadt lately, i noticed the extreme positive camber on almost all of the really old cars. The guy in the museum couldn't really explain it to me, so i thought i would aks here. Would be happy to see a video explaining this!

[@marc0pelot934]

Here's a quick summary of the consequences of changing your camber. If you want to try it out for yourself, all you have to do is buy Gran Turismo, the best console car simulation that lets you change this setting, so you can feel it at your fingertips!

[@albertpapikyants]

I was ready an article witch said that the M4 GTS is water injected. Can you make a video on the explaining how that works

[@EngineeringExplained]

Already have! :) kzbin.info/www/bejne/ipDPdnaYoJmHrbc (Just ignore the methanol part, works the same way).

[@scotta9114]

Friend had a Mini Cooper with direct injection. Started running badly. Cost over 600 bucks to get the intake valves cleaned. Great video BTW.

[@5jjt]

You can use an oil filter due to one side being threaded, insert an adapter there, then make a hole on the opposite side with another adapter. There may be some obvious downsides to this design, but it will work inexpensively.

[@enb3810]

Liked because of the honesty at the end. Everyone seems too sensitive these days, worrying about what people will think of their videos. Thanks for the great information.

[@MrManuel1329]

Cant you just route the oil in the catch can, back to the oil pan of the engine? So that people don't have to worry about changing the oil in the can or would that contaminate the oil to much?

[@NecessaryJerry]

Yes..contaminated.

[@KlueBat]

The stuff that gets caught in the catch can is really nasty. You don't want that back in your crank case if you can avoid it.

[@DAVe3283]

KlueBat The LB7 Duramax had that setup from the factory, and 10,000 mile oil change intervals. Mine has 312,000 miles on it, and there are many with much higher than that. All that stuff is already in your crank case, that's where the PCV is coming from. The lighter stuff (water, fuel) cokes off and goes out with the air. It doesn't hurt to keep it separate, but I don't think it really helps much either.

[@computiNATEor]

Yes, you can, as long as the oil changes are completed on time. BMWs with the M54 inline-6 use a "CCV" system (crankcase ventilation system) that does just that. Problem is, the CCV system in those engines is all plastic, and will eventually crack; especially in cold climates, where the oil vapors/residue/water can freeze overnight. In bad cases, CCV failure has caused hydrolocked engines, when the engine has sucked oil directly into the combustion chambers from the oil pan.

[@TheEdudo]

i have a 300 TDi land rover engine it has a cyclonic oil separator or catch can, it has one inlet and two outlets, one goes directly to the intake hose, the other that is at the bottom of the can, after a funnel type form, goes directly to the crank case dumping the oil separated, but anyways i get a couple of spoons of oil into the intake.

[@soberburnouts]

As you said in this video, that this is another added maintenance task. I own a 2013 mazdaspeed 3 that I bought at 26k miles and I'm at 82k currently, which I daily. I bought it stock and it's now full bolt on with aftermarket intake, turbo inlet pipe, high pressure fuel pump internals, catless downpipe, catless racepipe, aftermarket 3.75 inch ETS top mount intercooler, aftermarket go fast bits respons bpv/bov along with a few other power mods. I'm pretty much full bolt on minus cat back exhaust because I honestly love the sound of my stock exhaust with catless downpipes. I am currently running versatuner for tuning software and have tuned my car entirely myself. I never paid a pro tuner to tune my car and learned how to tune over the last 1.5 years. My car rolls flawless. I take care of the maintenance better than 90% of car owners. When I first got my car, I virtual dynoed it at 261whp 277wtq. Over the course of the 2 years I've been slowly modifying my car and my most recent virtual dyno pull got me 331whp and 349wtq. My cars got 80k and is running pump gas, shell 93 vpower nitro. Compression is great, leakdown is acceptable. I've built this car entirely by myself as my first tuner car and I think I'm doing things right, but I'm still learning every day, and I learn a ton ton ton from your videos. Also, I drive 30k a year.. you said in your video that OCCs are just another added maintenance thing that people are to lazy to install and maintain in short terms. Do you personally think I should be running at least one OCC to the intake to catch blow by? Like do you think it's worth doing? If so I'll grab one, I dont mind the added maintenance. And also, are there other parts that you suggest I should get to help prolong the life of my car that might be a hassle to maintain but offer good benefits?? If so, could you give me some clue or ideas of parts I should get to extend the life and health of my car? I'd like to also mention that when I got the car, it was only pushing 12-14 pounds of boost, and since the mods and all my diy tuning I'm hitting close to 24psi with about 10° of timing and it runs very strong. I just want to extend the life of my car and I'm still learning, so if you have any pointers or could send me in the right direction on some mods I should have the keep my car solid, it would be greatly appreciated, even if they're more to maintain. Thank you very much. If you ever have the chance to give me a call or something could you? and just ask you for some advice and like tips and pointers on things I don't quite understand. Id even be more than willing to offer you money just for an hour of your time! Ty

[@IllusionInfusion]

You know, you forgot to mention how this is far more important on a direct injection engine since you don't have fuel constantly flowing over the intake valve to keep it relatively free of carbon build up like you would with port injection.

[@Enlowra]

I have a turbo charged 1.6L GDI in my 2014 kia forte, I've been using CRC and the seafoam intake cleaners to keep up with the carbon build up. I was always curious how much material gets recirculated and caught in the catch can, so I got a cheap amazon special to test out. I found the PCV in the kia book, made that the input of the catch can, and the outlet of the can finished at the intake manifold. I drove 80 miles and checked it the first time, there was enough fluid to fill a whiskey shot glass halfway full. I put a ball of fine steel wool in the empty can to help catch particles. I think I'm a little late putting a can on the car since it just hit 100k miles lol. It works well enough that im going to start looking at catch cans for my other vehicles.

[@AnthonyJ350]

With your background, do you prefer a "closed system" or vent to atmosphere?

[@JodBronson]

I did my Dad's Truck with Vent since I see a lot of Moisture. If you see a lot of Moisture in the Oil Cap, vent it out... This will help your Engine runs smoother... Start better in the Cold / Morning / Rains too :D.

[@chris2790]

Vent to atmosphere is bad in terms of emissions.

[@JodBronson]

+Chris AF - Either way will be bad.... In my case, I have moisture problems.... If we sit the there and keep cranking the Engine, we are actually wasting gas / un-burnt fuel coming out for the tail pipe and that would lead to more pollution :(((((

[@mazenimad]

favourite channel for car info, rarely find that much info anywhere. thanks engineering explained

[@wizkid22]

Should have talked a bit about Air Oil Separators

[@dumamilk]

exactly what i was thinking

[@karlanguiano5214]

Ditto.

[@jasonw7053]

It's the same thing pretty much

[@Bdj2012]

Thanks for explaining! Question though, does that oil residue coming into the cylinder above the piston provide any appreciable lubrication benefit?

[@RcHDProductions]

Great video Jason! But I have one question. Does the oil that passes through the pcv valve help lubricating the upper piston walls? Is there a drawback of using a oil catch can in addition to the maintenance?

[@JoeJoe-pv7gm]

Without a breather on the catch can the pressure can build up and make things worse

[@SlotPoint]

Just bought and installed the E.N.D.Y.N. catch can for my Frankenstein B20V. The benefits are ridiculous, I can absolutely feel the difference; especially since B20 blocks do not have a PCV valve. Awesome explanation btw!

My mechanic said the following about Oil Catch Cans: "Those are crap. They are for people that have worn-out engines that can't afford to have them rebuilt."

[@colubrinedeucecreative]

Blowby is something all engines experience, though as an engine gets older and the rings and chambers get wore out, you get more blowby, thereby increasing the amount of oil you would get being re burned, and therefore making the car smoke more. That doesn't mean that you don't have blowby on a newly rebuilt engine, which leads to excess oil being burned, and caking on the valves and cylinders, increasing the wear on engine, making you have bad blowby earlier on with an engine. So yeah if you want to rebuild your engines sooner than a person that takes this precaution, then go ahead. Most people don't worry about it too much, except for the people pushing a lot of HP out of their engines, as higher speeds means more blowby which makes way more oil mist. especially those with turbo or supercharger set ups, literally forcing more air into the pistons.

[@whydoihave6neutrals772]

Gábriel Priòre he wants you buy a new engine haha what a spaz

[@intestinalworm1202]

Well done - remember as a kid when my dad had to remove and clean a gummed-up and jammed PCV valve in our family car.

[@MostGenericUser]

4:20 video length... the only oil that catch can be catching is cannabis oil

[@johnsmathers190]

Ford 2.7 with two turbos, my question is, does each turbo need a separate catch can? Or only one on the passenger side.

[@RLG261]

I like my installation of catch can. Get about one teaspoon of oil every 700 miles. Even have a video showing the system.

[@jevonrussell3159]

Can u make a vid or explain in a reply how this will work on a Ford that has Direct Fuel Injectors?

[@TheFJG23]

How often do you have to drain the oil?

[@SuperVitz]

TheFJG23 probably at least during each oil change?

[@a.wheeler7731]

Depends on how you drive and how good your can is, but once a month or more often for me. I do mine every 2-3 weeks. I got about 14 oz of oil caught in 5k miles.

[@rixiv7868]

A. Wheeler God damn that much?

[@duranbailiff5337]

When cleaning the throttle body on my wife's 2004 Buick LeSabre, I found it difficult to clean both sides, so I removed it from the intake. The front side looked pretty good and had probably been cleaned in the past (used car). The intake manifold side was incredibly coked up. There was in excess of 3/8" buildup- and I had never seen any engine that dirty before. I plan on putting a catch can someday to prevent this from happening again.

[@randomrud]

They catch free oil

[@jonathanguach4709]

I had a catch can that an inexperienced mechanic put in. The catch can only had one port, and it connected directly to the engine block. All it did was suck up all the oil from the block, kept having to refill every other week. After a 2 months the car was running horribly. Apparently not only did the oil go to the catch can, it also built up on the pistons, and valves. Had to take it all apart and pretty much rebuild the motor again. Hard lesson learned.

[@YOURMOMxo69xo]

If you're able to rebuild your engine why would you have another mechanic put in an oil catch can. In most cases they take like 20 minuets to install...

[@HATECELL]

Is there a specific reason why the air (and oil mist) does get re-routed from the PCV-Valve into the intake instead of just releasing that stuff into the environment?

[@EngineeringExplained]

+HATECELL so that you're not releasing it into the environment.

[@danielwoods404]

+Jon Rosenburg HAH!

[@markg7030]

PCV started in the 1960's. Cars used to vent crankcase vapors to atmosphere.

[@tracylewis3926]

The PCV system does far more than just address pollution. It performs several critical functions to keep your engine alive and long lasting. And that requires an evacuation suction source to remove the damaging compounds always entering as "blow-by" before it has a chance to settle and mix with the engine oil, as once mixed, it is there to stay. These compounds are as follows: Water, unburnt raw fuel, sulfuric acid, and abrasive particulate matter. Today's full synthetic engine oils will last 10's of thousands of miles if no contaminates are ingested, so that is where the PCV system comes in. All have a Fresh/Clean side where filtered fresh MAF metered air enters one portion of the crankcase, and flushes and replaces the Foul/Dirty vapors that are evacuated (sucked out) the opposite bank or portion. If you just vent to the air, your taking technology back to the pre-1960's when all engines "vented" using road draft tubes, and even changing oil every 1200-1500 miles (the standard back then) engine wore out and needed a total rebuild by 40-50k miles. It was after the Feds mandated the PCV system to reduce ground water pollution caused by oil run off from the roads that these same engines, using same oils and change intervals now were lasting 100-150k miles. And unexpected result of the PCV system as it was discovered these damaging contaminates were now being removed before they could settle into the engine oil. Another issue is pressure in the crankcase. If you do not use a strong suction source to evacuate these damaging suspended contaminates, then pressure builds to the point of being able to vent, and only a small amount of these actually exit the engine before they settle and mix. ANd simple flow dynamics dictates pressure will always be higher behind any vent in order to vent. This causes another issue, and that is piston ring flutter. Piston rings are designed to see pressure above, and suction below them to seal properly and maintain stability. When you remove the suction to the crankcase the intake manifold provides, then the pressure allowed to be present below the pistons causes increased blow-by and wear over time to the rings edges as well as the cylinder walls from the "ring flutter". You also then have parasitic power loss if the pistons have to fight the pressure in the crankcase on each down stroke. Lot's more to explain, but that should cover most of the question w/out writing a novel. Also, all "catchcans" are not created equal. The simple empty cans with fittings welded on allow most of these contaminates to pass right through trapping only some oil still causing the issues your attempting to prevent. Most cans, even the biggest brand names only trap 15-30% of the total "gunk" you want to prevent from ingestion. Look at one that is 95% plus effective like Elite Engineering's E2-X line, or the original RX (not the cheap copies pretending to be RX, or the latest from Tracy Lewis Performance through Jegs or direct from them www.TracyLewisPerformance.com Hope this helps!

[@theq4602]

Old school 2 stroke diesels used to just let it drip onto the ground. Often time on a cold morning youd find a big puddle of oil underneath your truck. If you didn't the advice was to top off her oil. Lets just say the EPA hates these engines.

[@CarsnStuff]

One of the things i've done with my supra is vent it into open atmosphere. after my oil catch can. The thing about supra's is they are known for blow by so one of the first things we have to do when modifying our cars is opening up the holes and ports for the vents on the valve covers. If you don't you actually run the risk of blowing front and rear main oil seals. I've seen it happen and had it happen to me. Soon as i opened up my ports from about a -6 to a -10 an fitting i don't have the problem any more. I have a cheap oil catch can, so it has no baffles or filters inside it. So it catches the oil and air mixture and vents out the rest outside. They are good things to have considering it keeps oil vapor from entering your combustion chamber and causing build up.

[@devinsmith4151]

Not needed anymore in some modern engines. The crankcase breather system is built-in the valve cover and has an oil separator.

[@JodBronson]

If you have a lot of Blow-By or a least when you look into your Oil Cap and see a lot of Moisture when Engine is Hot or see a lot of Moisture in the Muffler/Exhaust.... This will help a lot especially Starting issues! I installed this in my Dad's Truck after seeing a lot of Moisture in the Oil Cap / Muffler / Exhaust and Hard Start of Humid / Cold / Rain Morning / Nights. Now the Trucks starts right away and works really smooth too. BTW... I see my Dad always have problems starting in the Morning or when Rain out. I also see a lot of Steam coming out of Oil Cap when the Engine gets Hot! Once I install the Oil Catch Can with a Filter for venting, somehow it solved it, especially Hard Starting in the Morning / Nights!

[@skun80]

Now for turbocharged engines please!!!!!! :) On turbocharged engines the PCV becomes little more complex due to vacum to positive pressure at intake manifold. Install an Oil Catch Tank on a turbocharged engine is the tipical theme with tones of pages on internet but even that major part of people install this in the wrong way. Please explain to the world how to do this the right way

[@charliedee9276]

Made a catch can from the body of a Maglite for my 74 Harley. The stock breather was just a downdraft tube aimed at the ground. A Chore Boy scouring pad makes a great baffle and now I don't have a oil covered bike after a blast down the freeway.

[@MistahMOB]

Awesome video man been waiting for a good explanation of this thank you

[@Soggstermainia]

If you have a car you care well for is it worth adding this to the system, or could it cause issues by changing the characteristics of the feedback loop as it were?

[@HAL-dm1eh]

Catch Cans are used by Camaro owners to catch the butthurt from losing to a Mustang 5.0L.

[@XjDrZ]

All while the mustangs are running over the spectators!

[@Mondos2001]

+RedBeard109 👏true

[@Mondos2001]

Louie Watson si señor, but the new corvette, that a different story.

[@petermoger8135]

+RedBeard109 at least that 5.0 can create enough torque to drag the crowds with it. I don't see any Camaros taking out 20 people without loosing any speed.

[@Jman42093]

Devin Actually stock for stock the mustang is faster for all years except the 2016 and up camaros and they are quite impressive.

[@AssassinsGprods]

Is there any difference between this system and just having a breather outputting the contaminated gases from the crank case to the environment? Only reason that comes to mind is that it would be for the sake of being eco friendly.

[@TautologyTechSystems]

Hey I know you can help me. Just bought a 2017 wrx sti and I'm considering an AOS or catch can. I do not plan on ever doing any other mods, and this is strictly my daily driver that I like to have some occasional fun in. Do you think this is a necessary thing to do? I'm really just concerned with ringland failure and I've been reading that this would be an excellent investment.

[@jtpro0244]

It's probably not necessary. It definitely won't hurt your car, and a can will help prevent the dirtying of the top of the pistons and valves. And, the fact your car is turbo charged means there is more positive crank pressure, especially as blowby increases with age/wear. I'd say if you want to do a project and don't mind the maintenance, go for it!

[@MD-pz3cn]

EJ motors use port injection which takes care of the intake valve issue. However, catch cans/AOS are still a good idea on EJs. Since these mods reduce the amount of oil going back into the intake tract, less oil = less chance of knock. This is because the oil isn't diluting the air fuel mixture during the intake stroke which would in turn lower the knock resistance of said mixture and cause pre-detonation during the compression stroke. As long as EJ motor cars are driven correctly...letting the oil get up to operating temp before pushing the car hard, ensuring oil levels are always correct, using the correct oil (NO Mobil1), and not requesting high load from the motor in the lower rev range, a lot of bearing and ringland issues will be gone.

[@MrAquinas1]

What's wrong with Mobil 1?

[@MD-pz3cn]

In short, it shears down over time to a weight closer to that of a 20w at operating temp. This shear is designed to occur on purpose in order to lower friction between engine internals and increase, or at least maintain fuel mileage. This then in turn brands the oil as a "resource conserving" oil and hold the ILSAC GF-5 certification. All find and dandy, but EJs are driven hard by their owners at (inappropriate) times. A "thin" oil won't protect crankshaft and/or connecting rod bearings during high load inside the cylinder and that's when you'll see rod knock as a result of the crank and/or con rod bearing getting spun because the thin oil gets pressed out of that area and cannot provide sufficient protection. This is what my research of oil+turbo Subaru motors has led me to believe. I would like to be corrected if I am wrong.

[@MrAquinas1]

Thanks. What do you recommend? Royal Purple? Red Line? Castro? Valvoline? As a road racing fan, I've actually seen professional teams using the first two in Le Mans type race cars at Lime Rock. But racing use can be different. They are less concerned with detergents since they frequently tear down their engines.

[@tweake885]

i havn't read all the comments but one thing to keep in mind is that some manufactures purposely design the breather system so a certain amount of oil gets into the intake. this helps reduce inlet valve seat erosion. most gunk in the intake comes from EGR systems. provent make a great catch can imho. you can plumb catch can to return the oil to the sump. that can be important on certain motors that throw out large amounts of oil out the breather.

[@blaqwhole4998]

20 years ago we just called it "crank case ventilation" and everyone knew what it was.

[@gonzccs]

It also helps to obtain a cleaner combustion and so extends the life of the catalytic converter, O2 sensors on the exhaust system and less pollution... it is a great Idea! Thanks for this and all your great work!

[@prayerpowersr854]

make some videos aboot motorcycles

[@spettro9]

If you've ever cleaned an Intake Manifold, you will totally be into oil catch cans... Good video and explanations, thank you!

[@FroZe2223]

Second

[@FroZe2223]

Look mom.

[@50desoto1]

I am so glad you did this video! I asked for this months ago (not the reason you did the video I am sure, but still) and so happy to see it! Wish you covered the importance of filtering the contaminants from GDi vehicles and others where the fuel doesnt spray the valves leading to "maintenance" by the dealer to the tune of pulling intake manifolds and cleaning valves manually.

[@patw52pb1]

Additional note: Most turbocharged/supercharged or boosted applications do not route the hose/tubing back into the intake runner either from the factory or for aftermarket installations. The primary purpose of the catch can is to separate vapor and liquids from the crankcase/blow-by stream, vent the gases and provide a reservoir for the separated and collected liquids.

[@patw52pb1]

Guillermo Lovato Keyword... "Most"

[@mgayar16]

What you mean is higher end cars, because I know for a fact, that the wrx,mazdaspeed6,s2000,gti,srt4,and Golf r route it into the intake

[@patw52pb1]

OK wise guys. If the intake runners are under pressure (15 PSI) and the crankcase pressure (~10PSI) is vented to the intake runners, where does the pressure go? There has to be a difference of pressure to promote flow. High pressure flows to low pressure, it is physics. Put the crankcase under 10 PSI pressure and it will begin to push oil past every gasket and seal.

[@mgayar16]

Exactly what Robert said the is a check valve in almost every new boosted car to prevent it from going downstream. Almost every boosted car uses this but it tends to make the car run a bit rich in idle due to the restrictions

[@robertnoble3733]

Great video! Now you need to do the follow-on video that tells why modern GDI engines really need a good catch can, whereas your older carbureted or conventional fuel-injected engine did not. (ie, automakers did not properly evaluate the long-term effects of GDI on intake deposits). Dealers want anywhere from $500 to $800 to clean your intake ports and valves. Some automakers are discussing adding an additional fuel injector within the intake manifold just to keep the intake clean. That's a nice idea for the future, but it doesn't help those with existing GDI vehicles.

[@jaimeluis7434]

Thank you so much for this video. A few months ago I mentioned you in a comment that a video explaining what an oil catch can is. Thank you, again. Another video that I haven't seen is explaining the differences on a downpipe with catalytic and without it. That would be awesome. Good day to you.

[@russhellmy]

I enjoy your videos and appreciate the time and effort you put into research and data , not just BS & hyperbole like many auto commentators. As such I would love to see your opinion on "Bypass Oil Filters" especially with regard to larger Diesel Vehicles such as SUVs and 4x4s. I have a 2015 Ford Ranger 3.2L Wildtrak with 100k miles of which 80-90% are from a 50miles each way daily motorway commute. I use the recommended 5W30 Fully Synthetic Oil and do the 7.5k mile oil changes myself. I am considering adding a Bypass Oil Filter system to improve oil quality and possibly extend the oil change interval to 15k km since most of my driving is straightline 60-80m/hr motorway driving which doesn't put a lot of stress on the engine or lubricant. I believe diesel engines due to the higher pressures and dirtier fuel will generally have more carbon and sulfur compounds enter the Oil. There are plenty of videos and lovely graphics by the "Bypass Oil Filter" sellers. But almost a complete lack of independent unbiased assessment of their effectiveness. I often see these Oil Bypass Filter systems used in Heavy excavation equipment for both their diesel engine oil as well as their hydraulic oil systems and also in stationary hydraulic systems and believe they are also used widely in Semi truck industry, but again there doesn't seem to be much published independent assessment of these systems I expect with your fleet contacts and industry experience you would be able to give a valuable opinion on these Bypass Oil FIlter Systems. Thanks

[@RussianPIMP64]

Very well explained as always! But 99% of catch cans on the market dont actually have the filter to stop the oil from flowing back into the intake, even one which I bought from my local auto store doesn't have one. Any tips of which brand to use? I also heard that shoving some metal scourers/ steel wool into the can can help?

[@costantineyoussif6679]

Same question here? Any recommendations on high quality OCC yet ?

[@cjones7854]

In the Mighty Car Mods video on installing an oil catch can, they mention being wary of plumbing a catch can directly to the pcv valve because it can have an affect on the reading of an air flow meter (not sure if this is a problem if your car uses a manifold pressure sensor instead). I think that is what they were saying. Even on the forums for my car there seems to be some discrepancy on the correct way to plumb it between the pcv, or the rocker covers, or both. All cars are different but I was curious if anyone had any thoughts on this.

[@190055joe]

Traditionally the crank was vented via a tube just under the engine , then came PCV idea also its not air that gets shoved back into the inlet manifold their exhaust fumes mixed with oil vapours .

[@flybobbie1449]

Light aircraft aero engines don't even route the vapours back into the engine, they are dumped over board.Amazing what gunk and moisture drips out after landing.

[@robertnoble3733]

Love your videos! Comments on this video: you should have pointed out that (a) older fuel injection systems sprayed fuel into the intake stream ahead of the intake valves, cleaning them with a continuous spray of gasoline, (b) the problem is worse on higher compression engines, eg turbocharged engines, and (c) the dealers want between $600 and $900 to remove all your intake "stuff" and blast your intake valves with walnut shells. If the catch can halves the frequency of valve cleaning operations, even the Black Forest catch can ($300+) will pay for itself quickly.

[@Bairdogg]

I have a question thats really been bugging me and maybe you can give me an answer. My father has a hardtop convertible system that folds itself into the trunk, that system must way a minimum of 500lbs (E93 weighs 700 pounds more than the standard coupe). Would the car be faster with the top up or down? I'm sure the difference is hardly noticeable but imagine something like an autocross car. Its obviously far more aerodynamic with the top up, but an extra 500-700 pounds over the rear wheels should make something of a difference to acceleration with even more grip, but i imagine would harm the cornering ability with the weight distribution so focused towards the rear. Theres obviously many more factors to consider but I'm sure youre already aware of them. Ive looked it up but have never found any information about the subject.

[@rohanmore1774]

I have seen most of your videos and i must say you are simply awesome and passionate about engineering. I am pursuing mechanical engineering and aspire to acquire deep knowledge like you :) Hats off bro !!!!!!

[@DENicholsAutoBravado]

I have watched SOOO many videos on the internet about these. I already understood the concept, but the one thing NO ONE talked about Jason of course did. It can't just be an empty vessel to get good results. It has to have some sort of baffling or filter, Jason says, so that the oil doesn't just keep on misting through. Now to buy some cheap eBay ones and cut them open so I can tell people if the specific cheap ones that I buy work...sorry for cars that are running good, a catch can could be a waste of money, but some cars will really surprise you. One great tip I got from the Scotty Kilmer Google Plus community was that you should just run an inline filter on your PCV hose to see if a catch can will even help you. :) Cheers. Fans, I guess I should watch the next 2 minutes of video...I'll comment again if I have more feedback from things I learned. Thanks for a great video again!

[@DENicholsAutoBravado]

Most people will certainly be unaware of dirty pistons and even more so of valves in their engine, unless they have a direct injection engine and they are facing high repairs...that said, to anyone who's enjoyed ChrisFix's videos about looking into an engine and seeing what works to clean them, on the short of it, it looks like we all have dirty needy engines, but Chris said that he struggled to find cars to do more tests because most pistons are quite clean...at least in his experience. By the time a car sees me it usually has big problems, so I mostly see very carboned up piston heads (I'm a diagnostic technician and stay mostly busy with challenges that most don't learn to do, but like SouthMainAutoRepair or SMAR, I'd say if I can do it, you can do it too.).

[@avinashclt]

Doesn't most modern engine systems that use a PCV also incorporate a oil separator in them? I know the efficiency of oil separator is debatable, but instead of having something to regularly drain out, the oil separator returns the liquid oil (albeit with some contaminants) back to the sump. And we also know why manufacturers have specific oil requirements over and above the standard SAE/ACEA metrics, it accounts for the oil with the contaminants retaining it's properties over a specified service interval. So without talking about oil separators, which most modern engines have, having a lazy label for not having a catch can doesn't sound fair.

[@CarsSimplified]

That oil that gets drained out: is it spent/not recommended for reuse? It seems like that could be drained back into the crankcase (using a valve and tube leading back to the engine) when the engine is shut off to eliminate the need to manually drain it. If that oil is past its useful life, though, I can see why that wouldn't be done.

[@CondoreComputing]

The issue is that it is contaminated with partially/unburned fuel and byproducts, and you really want to keep fuel contamination in your oil as low as you can.

[@RoadrunGTI]

I'd reiterate the idea of going into slightly more detail for these types of videos. For a topic like catch cans, there are certainly many more arguments for and against catch cans. For cold climates, there's the potential of freezing lines and plugging crankcase ventilation. Also, there are various types of catch cans, including vent to atmosphere and recirculating.

[@tt-rs1457]

Regarding to that, it 's also important that the airflow restriction is keeping as small as it could be. Otherwise the crankcasepressure is getting high and causes Oilleaks. So, you have to keep the routing short and the catch can should not contain a Brassfilter in it.

[@string2155]

His diagram is different from other engines. PCV valve is right on the exit of the valve cover. Others are attached on the intake. In other set ups, oil catch cans also help keep pcv valves last longer.

[@rhkips]

What about catch cans that drain back to the block? My old Pontiac's PCV system included a catch can from the factory with an air/oil separator integrated into the block itself, complete with a series of baffles. It was an unusually complicated system that took me a week or two to completely figure out...

[@mickm5097]

I am curious as to whether the cleaner air entering an intake would have an effect on the O2 sensor readings. As a long time owner of Toyotas, I've dealt with their finicky O2 sensors from time to time, and it would make sense that if the engine with an OCC isn't burning blow by oil, the exhaust has to be cleaner and the sensors should be less apt to throw a code and turn on the check engine light. But is that a reality?

[@tomasjones3755]

Loved the vid. Good presentation. I found out about separators, years ago, when I added HHO; to my car. Just bought a new vehicle and wanted to see what has changed. I'm very happy, that more people are paying attention.

[@kagmich5796]

Another reason (for turbo vehicles) is to prevent buildup of oil getting into the turbo intercooler and/or getting this "sludge" sprayed on your turbo vanes.

[@stevewaclo167]

My 1987 Alfa Spider with a Bosch L-Jetronic fuel delivery system uses an oil mist separator that acts as a catch can with one difference: condensed oil most is captured at the bottom of device has a tube that leads to a connector at the bottom of the dip stick tube and returns the oil (and whatever else 😟) back to the crankcase. I'm not particularly lazy and have considered disconnecting that return line and "catching" that material for proper disposal.

[@designspm]

Taking in consideration both vented and recirculated catch can systems take the oil thrown on pcv, these are the other advantadges/disadvantages: Vented catch cans: Advantages - no hot oil breather to engine -> lower intake temperatures -> less air density -> more air inside the combustion chamber in each cycle -> performance gains (take in consideration efi engines will compensate the mixture while others not) Disadvantages - No intake vacuum to extract the fumes -> less fumes extracted from crankcase -> faster oil contamination and a sludgy bottom engine - Sometimes engine runs cooler than designed -> fuel consumption will be higher - More pollution to air and smoke smell inside car Recirculated catch cans: The opposite of vented catch cans but the intake temperatures will be almost the same as in default engine without catch can For petrol engines vented solution is perfect no question about it. For diesel engines, if your piston rings are good and don't let much smoke to come inside the crankcase the vented solution is enough, if your rings are worn you need to use a recirculated system since you need to extract more fumes generated and the intake vacuum will help a lot on that

[@sj1260]

My question. Does it matter if the baffle or filter from the catch can is connected on the PCV line? Or from the crankcase line? I believe that I've seen some connecting the crank line to the filter line of the catch can, and some the other way around. I'm a little confused

[@TypeVertigo]

Hi Jason, how often would you have to drain the contents of a typical oil catch can if you have one installed? Would it be convenient enough to time the drain interval such that it coincides with the oil change interval? Great video by the way - I've heard of these but yours is the first time I've heard them explained in detail.

[@VCBird6]

Having run one for a number of years on an older Honda, I can safely say that unless your motor has some pretty bad rings (or you're running some insane cylinder pressures), you won't have to drain the can more often than your oil change interval :)

[@TypeVertigo]

Thanks for the reply. Yep, car's a 2005 Honda Jazz (aka Fit). If an oil catch can's going to help keep it ticking for 11 more years then it might be a good mod to do.

[@QuackLoud]

Thanks for a very thorough explanation. Was watching another KZbin video where she was installing an Oil Catch Can and I had no idea what it was for. Now I know.

[@ccfckieran1440]

Gotta say love how u draw diagram and stuff so easy to understand great video 💯

[@stuckinmygarage6220]

Oil catch vs oil gas separator in relation to emissions? I was hoping to learn more about the subtle differences. Also, there was no reference/link to the piston rings video mentioned. Thank you for the info.

[@msanchez7317]

Where's the V man, where's the V?! In all seriousness, enjoying the videos I've watched so far. Watched your review on the Subaru WRX STi but ended up with a Mustang GT - love it! Keep the content coming.

[@thedeukful]

Question for you, on my motorcycle I made a “catch hose” instead of a can. The way it is set up is hose out of crank case breather outlet, T connector with a piece of hose and breather at the end of it going up, longer piece of hose with drain plug going down. It collects oil but there is still a good amount of wet vapor that escapes out the breather and therefore gets all over the top of my engine. Can I put a vent somewhere, stuff the top hose with steel wool, or reposition in a different way to get rid of this problem?

[@TheEdudo]

i have a question it deserves to be answered, there is a myth (or maybe it is not?) that states that blowby gases containing oil mist routed to the intake valves are designed like this to lubricate the valve seal faces and seating,it is so??

[@marcoslima1086]

Why is the air rerouted to the engine? To decrease pollution? Wouldn't it be better if the engine took only fresh airflow? And also, does the PCV affect performance? For better or for worse? Thanks :)

[@Wolfsgejaule]

Exactly, it's so the toxic gasses and oil don't get released into the environment but rather get burned off cleanly

[@fixitluis]

you should do a video on vacuum pumps for crankcase ventilation, its great for the life of the seals and helps piston seal

[@1979-b9t]

Hi Jason, there's something I don't understand: Is the blow-by mist (oil/gases) scavenged by the PCV valve and its system completely canalised by the catch can after all ? The catch can seems to recover only a part but not the integrity of this mist, as a part finds its way into the combustion chamber.

[@gedavids84]

My 2001 SAAB had an oil trap on its PCV system, but it had a drain on the bottom to return it to the sump. Don't know why more OEMs and aftermarkets don't adopt this design.

[@johannesvanzyl9459]

SAAB was always in another class. But could also be that they borrowed the idea from their Scania heavy truck division?

[@scotta9114]

SAAB was the pioneer car company. Many of the features in today's cars were first implemented by SAAB. And I only drive SAAB cars. Since they are gone, will have to switch to another brand someday. Uggh.

[@Bmarsters]

Adding a Catch Can to the F150 EcoBoost engines is getting fairly common, especially when tuned and when used for towing. I'm considering a catch can for my 2015 F150 , but would like to know if anyone has a recommendation.

[@andrewiannello6548]

Would oil leaking from turbo seal find its way into a catch can? Would it only work if the intake connection was at the bottom of the intake pipe so it gravity feeds back to the can? Just trying to establish if you could use the catch can as an indicator for increased oil consumption, obviously if you had a baseline already from the crankcase vapours only.

[@charms1944]

Can't believe you're almost to a million subscribers!! Been watching you since before your integra got salvaged

[@TheLorenzoFilth]

Oil does not need to be drained as all the catch cans i know have an oïl return tube to the crankcase .There's no fuel in oïl unless the engine has a serious problem no ?Great video anyway with a cool sketch to understand what is blow-by.

[@cammando117]

There are catch cans with breather filters I was under the impression that they fill up with oil and the air shoots to the atmosphere but is filters with the tiny filter some of them have

[@jm31772]

I always wanted to buy one, but now after watching your video, I'm convinced. Thanks

[@WorkPlayDrive]

Excellent video as always, I get asked all the time about Catch Cans now I have a trusted resource to send them to for a clear quick explanation.

[@sn95cobra]

@engineering explained - Is it okay to remove the fresh air source? For example, on a new 5.0 liter Mustang engine, one side is the PCV valve that routes to the throttle body. The other side is connected to the intake tube for fresh air intake. Most catch can systems route both of these to the can, and then the output goes back into the throttle body input. The air intake port is capped off.