How Does a PCV System Work - Also Testing and Inspection of the PCV Valve

[@vijayam1]

Probably one of the best explanations in KZbin mentioning why PCV always has to be used with a breather tube, that clears most of my doubts. Great video brother!

[@MR-nl8xr]

The part where he mentioned how the pressure from the Crankcase travels through the Oil Way Tubes (that normally run from the Valve Head section down back to the Crankcase base/Reservoir to get resent back to the Oil Pan) up into the Valve Head section is what did it for me. Never understood what a PCV is doing on top of the engine head if the Crankcase is down below.

[@timanderson9466]

PS: This is how videos should be produced. Straight to the point and informative.

[@bradford_shaun_murray]

1990s cable tv style.

[@juperrr]

@@bradford_shaun_murray Exactly dude.

[@pnswg01]

Great video. Explained well. I like the fact that you explain with the diagrams and then show a real example. Very clear and understandable. Keep up the good work.

[@spelunkerd]

The PCV is one of those little marvels of universally adopted engineering. The simple appearance belies underlying complexity! No vacuum - closed to prevent backfire induced retrograde flow, high vacuum - minimal flow (at idle when you don't want a big swing of crankcase pressure), low vacuum - high flow when at wide open throttle the engine can easily take in extra blowby gas. Great practical summary!

[@cedricthompson4602]

spelunkerd o8u8o8k6

[@afundou]

and why bad working makes engine pipe smoking?

[@ironfistarrival]

Does Nice Blow Jobs , i guess !

[@chocolate_squiggle]

Just ruddy excellent. Dude thank you so so much. I've been watching more of your videos just in the last week, you have quite a gift for knowledge transfer. Not everyone is able to do that effectively. That diagram and the way you explained it really helped me understand PCV properly. I vaguely knew it was pressure equalisation but I struggled with how and why oil could traverse all the way up to the airbox, or an intake manifold - I've seen both. I see now it's not really being drawn all that way directly, it's just oil that was _already_ in the upper area doing normal stuff, and getting through PCV or breather hoses. I've done quite some work on my car this week, have more to do and I knew checking the PCV would be part of it. I just wasn't really sure why.

[@davidsimmons177]

Dude almost has a million subs and uses a 2x4 to hold hood I love it haha

[@RC-Heli835]

Thanks for all your helpful videos man. I think if they rattle they can still be bad. Someone told me you you should only be able to blow one way through the valve which lets you know that the valve actually does have enough spring tension to hold it closed.

[@jimdandy6472]

Good explanation, diagram and demonstration.

[@ll-yj6rh]

What happens if there's oil in the air filter box tube before throttle body

[@shaneavalon1392]

Very helpful info as usual.. quick question.. does a faulty pcv valve cause increase fuel consumption.??

[@phantasmagorezzyzx]

Great explanation, easy to understand! Thank you!

[@dimitrismavromatis8807]

Hi. I would like to ask something if the following is true: If you open the oil fill cap during operation at idle and put your hand close to the oil fill hole you should fill some gas pulsations. This is normal because the valve is almost closed. However, when you open the throttle, the pulsations are lost, since the pcv valve opens. Is this a way to check your pcv valve?

[@virc4541]

Thank you!! is a real good information for inspect and change the PCV Valve..greetings from Guatemala City!!!

[@jonb4667]

Thank you for explaining how the pcv system works. Now i really understand how the direction flows. Big Thank You

[@bimalkumar7952]

First time I learn from you about PCV valve ...thanks

[@Stumpy77]

Great video bro - no messing around, clear explanation and valuable info.

[@riblets1968]

Just the information I was looking for! I understand the basic principles involved but I didn't what constituted valid testing. Thank you very much, sir!

[@vasmajority45]

Could you explain how the blinker fluid works

[@gdzeek]

hold the bottle above your head, hold your eye open and slowly squeeze on the bottle while holding it just above your eye

[@MidwestDIY]

@@gdzeek I tried and it worked

[@gdzeek]

@@MidwestDIY contact lense users rejoice!

[@r.s.customz1502]

Ask a blonde chick driving while texting lol

[@RichardFanders]

When you open the throttle body there is no vacuum after the throttle body, there is actually positive pressure sometimes. There can be a vacuum before the throttle body at WOT hence why there is a breather before and after.

[@TravisHeinze]

6:00 Is that the common way to vacuu test the valve, with your finger? I have a Ford Focus that I want to test the pressure with.

[@samiuddin6696]

Excellent experiment for how to check PCV for its function. Jazakallah-o-Khair in this world

[@mateoseriosajr1022]

Its normal if u see some oil in the hose when you remove it from the pcv valve?

[@wavyjayy1350]

great vid, so if the valve is sucking where you were putting your finger then it should be good?

[@Chezilla]

5 Years later, still great info! Thx

[@irineosahagun1228]

Interesting and Educational video. Furthermore, may I ask if a small piece of pcv grommet which fell inside the port could cause problem in the future?.Many thanks buddy. Have a nice weekend. God Bless.

[@SlikLizrd]

YES. Broken pieces of grommet can cause plugging of oil passages. SOMETIMES, you can suck 'em out with a vacuum cleaner. Good Luck !!

[@crbourret]

Is it possible for the valve to get stuck open? And if so would it cause increased oil consumption?

[@ninemimesleft]

Also, would it still have suction if it's stuck open?

[@AstroVanTribe]

I just di the PCV valve in my '04 Astro van - The existing PCV valve tested fine BUT, when applying brake pressure when the vehicle was in gear it rattled wildly and was loud so I decided to replace it anyhow ($2.85) it seems to have solved my issue

[@waqarahmad9548]

As always, very informative. U r a genius.

[@nahid1981]

best explanation so far I found about pcv...thanks. Keep up the good work.

[@sunilayya8948]

Best explanation i have seen on this topic . Can you suggest a pcv valve replacement interval for a gdi turbo engine. Thanks.

[@abacus091]

good job Bro, please continue work hard, eastern Europe fans watching you

[@myRatchets]

abacus091 Awesome, we just getting warmed up. Great to hear I have fans around the world. :)

[@planet1250]

RatchetsAnd Wrenches I have watched all of your videos. A fan from Italy

[@cvcoco]

As part of maintenance, though, arent we supposed to wash out the valve with carb cleaner or wd-40 or something from time to time?

[@SlikLizrd]

As a part of your maintenance schedule, you should REPLACE the PCV Valve at 50,000-mile intervals.

[@rrazvanell]

To fully understand....the breather tube supplies air from the filter box to intake manifold? Because, when throttling the engine doesn't it create a vacuum at the end of the tube where is connected to the filter box ?

[@juperrr]

Pretty good explanation. Thank you !

[@dannyyarbrough915]

Thanks for posting if my Jeep is smoking a little and it's because of a bad pcv valve and I change it will the car stop smoking or is that from the calender, piston ring damage caused by the faulty pcv valve

[@garyr7027]

Well there is a little bit more to it. At idle when manifold pressures are high/"high vacuum," and low crankcase pressure pushing on one side of the valve, and suction on the other side of the valve, the valve will remain in the closed position. As throttle opens, manifold pressures drop opening the valve, relieving crankcase pressure. At idle a pcv valve should be closed, otherwise a vacuum leak is created, dropping manifold pressures, decreasing the valves ability to close. At idle a engine, unless it's wore out, doesn't really require crankcase pressures to be relieved, only at part or wide open throttle, for it is then the crankcase pressures build.

[@drudown3285]

Just changed mine. The old one had no rattle and no bounce inside. Glad I changed it!

[@ralphpittman6361]

Awesome video!! I’m actually running into some oil pressure issues. Decided to test my pcv valve just like in the video but the car did not want to start. Any reason why??? Any help would be greatly appreciated.

[@Forged_Garage]

Is it possible to relocate or add an extension where the pcv valve is installed? Because i have a 2009 toyota rav4 2ar-fe engine, and the pcv valve is located underneath the intake manifold, so to access it i need to remove the intake manifold first, alternative way is to lift it remove the passenger side front tire and splash guard to painfully access it, do you think by putting a extension hose will make any issue?

[@luislarriu3381]

You do a great job explaining things in detail

[@UsmanEhsan]

Is it important to let the recycled air back to manifold or else just catch can and let to atmosphere ??

[@francogalloso2167]

Good explanation of how pcv works. Thanks.

[@blinkskaterkc]

Thanks good vid. So if the pcv valve is off, would the pressure be able to escape from the crank case? Seems like it would. But I guess oil could escape too. Does the valve protect oil from getting into the intake?

[@myRatchets]

Yes, and thats how it was done back in the day (pre 1960's) they had a hose I believe that just let the crankcase pressure escape into the atmosphere. Now those are pollutants so you cant let them escape into the atmosphere anymore but through the pcv valve they get recycled back through the engine and burned off. The valve is supposed to keep oil from escaping into the intake but some minor amount will get into the intake no matter what.

[@terrywaters6186]

@@MattInIllinois But you're OK with dumping it into the air you breath and onto the highway.

[@ashleynaidoo6907]

Hi There, Thank you for the awesome videos. You have definitely improved my car/engine knowledge. I drive a volkswagen 1.8T polo gti 9N3. On idle, if I remove the oil cap, should I feel a vacuum?

[@metodraginii]

Great video. But is that the case with all vehicles? Are all of them ventilated through the valve casing? Why some use a PCV line coming directly from the crankcase and others are like this Toyota? Also I know some use an oil/air separator before the gasses are returned but it seems there is no such thing in this Toyota?

[@myRatchets]

Stefan Ovcharov Good questions, I am not sure. But if I had to guess I would say the newer the cars more likely they would use an oil catch, and older they are more likely they would use the vent directly from the crankcase. cheers

[@metodraginii]

RatchetsAnd Wrenches Thanx. Cheers.

[@MrRevto9k]

Does the PCV need vacuum to function properly?

[@MrBow54]

As always great video The best to you on this holiday season

[@myRatchets]

Thank you, same to you my friend. Cheers

[@jb6574]

Doesnt vacuum drop when you open the throttle plate

[@MarzNet256]

Yes. Increased flow reduces pressure. If you hookup a scan tool you can watch it change in realtime. I use a $20 OBD2 reader with bluetooth and $5 torque app on phone.

[@fermingarciaseoane8328]

Hey man i think that i have a problem with my pcv system, my motor is a sr20de from nissan, my car burns oil and i can see smoke coming out of the tailpipe when idling at cold starts (when i start riding and it heats the smoke disappears), i checked my pcv valve and its not clogged, do you think it could be the breather tube? Thanks a lot for your video, i thaught my engine was fckd up.

[@JoeBlowski]

Bad valve stem seals allow oil to leak down onto the top of one or more pistons causing exhaust smoke after being parked, but they usually don't leak fast enough to see smoke after the puddles burn off. It is impossible for the PCV system to cause visible exhaust smoke.

[@beachboardfan9544]

What if you have a drysump oiling system, would this still apply?

[@RabeaHussain]

if PCV is blocked , oil would leak from the engine ,right?, But wouldn't the blow by goes out the breather side ? instead of leaking from seals or gaskets ?

[@shuriKen469]

is it possible to clean the PCV valve with carb cleaner? got a GM truck where the valve is attached to the valve cover, so the whole cover ($100) would need to be replaced if the PCV valve goes bad.

[@fidelcatsro6948]

thank you senyor, by watching this video I learnt a lot of mysteries about the 4 darn odd looking pipeline from the cylinder blocks to a metal square contraption above which has an air suction hose from the carbs and another large hose to the breather box on my Suzuki bandit bike, it was a mystery all these 7 years and at least I know some of the basics now, especially that ticking noise when I throttle and its cause! you reckon I can get more ponies out the bike if I dead flange them up completely? never seen that odd pipe in older bikes anyway

[@tnamen1307]

Sir also check for the same at 6.20, the valve is sucking, but the hissing sound is still coming from the pcv valve.

[@tssci6774]

Many new cars use a fixed orifice instead of the vacuum controlled variable valve. So many people still think it works in the same way but it doesn't. A fixed orifice allows only so much air flow at idle, when vacuum is highest and crankcase gases are lowest. When the throttle opens, vacuum drops and thus air flow across the orifice is reduced substantially. Can you do another video on orifice type PCV systems.

[@careygonzalez2829]

so..... having Oil going up through my pcv valve to my throttle plate is Ok? I have a 2000 ford taurus duratec 24valve dohc engine and the hose set up is connected behind the Throttle plate. Just changed the PCV in it and there was a little oil at the bottom of the plate. Really appreciate your videos, by the way!

[@heyitschinoable]

Its always good to clean off that excess oil on the throttle body or throttle plate.

[@jddeefo1022]

Should this be changed out based on mileage, or test it and if it works leave it?

[@SlikLizrd]

The "rattle test" is inconclusive. DO NOT rely on the "rattle test". Simply REPLACE your PCV Valve at 50,000-mile intervals.

[@Losangelespharaohs]

do you reccomend a breather filter for a car to have a fast set up

[@DubsKey]

What is that part you first pointed your finger at on the crank case?

[@SolidVermillion]

Thanks so much for clearing all of that up. Nice touch adding testing procedures as well.

[@soufbel3455]

🌟Hi friend, in case of PCV valve stuck closed, the pressure will not be evacuated by the breather? 👍👍👍

[@zofa300]

Thanks for the video. I have camry 2007 4 cyl with 100, 000 miles. I changed the pcv valve, I see a blow by but no smoke and the car has plenty of power. However it consumes oil ~ 1 qt in 1000 miles when I was using Mobil 1 5w-20. The oil consumption improves to 1 qt in 2000 miles when using mobil 1 0w-20. My questions to you: 1-Does the blow by means the rings are worn even though there is no smoke at all? 2-How to tell if the blow by is normal or excessive? 3-Do you think the car can survive for another 100,000 miles? or need rings? Thanks

[@myRatchets]

+zofa300 I think there is a recall by Toyota that covers rebuilding the engine on your car, not sure if your year is covered or not. Apparently some piston ring excessive ware causes those engines to burn alot of oil. Do a google search you should find it. gl

[@zofa300]

+RatchetsAnd Wrenches Thanks for your reply. I am aware of fix that Toyota announced. It required more than a qt in 1000 miles. I am just afraid it I am slightly less than 1 qt for 1000 miles so I'd like to know what I should expect from this car if It just can run for 100,000 miles if I keep adding oil or there are many other issue. Any additional comment is appreciated. Thanks a lot

[@gordonkarschner8092]

zofa3

[@michaelmorris6575]

Great teaching! Thanks for sharing!

[@foreverwood1963]

Excellent explanation and illustrations

[@russelalmanzor4056]

For some reason my 2007 Mercedes E350 was burning oil like crazy for a few months and not sure why. I looked at the PCV valve and the hose wasn't attached to it... not sure why. I put it back on but now I'm worried. Have I caused damage to any components? While the hose/tube was off, there weren't any weird symptoms other than oil consumption. No rough idling or anything.

[@tokgaenz]

thank i like all your educational video , i learn many from it , i fix my good car and make it not working

[@tbowen12]

Do you think it can get stock open too?

[@jalatecompa]

If there are leaks on ccv ducts,, this could make a high fuel consumption on a 2001 jeep xj?

[@princesamuel1]

Perfect and straight to the point

[@davidkweller3089]

Hi, i have a dodge dakota 2006, and its burning oil, and blue smoke sometimes comes out, do you think its the PCV valve?

[@minhch3175]

very good video. What is year of the vehicle? seem toyota Camry or Celica? I have Celica GT 1990 ... wonder where is PCV valve located? can find any similar PCV valve you show!!

[@myRatchets]

Minh VC 95 camry, not sure of that year Toyota.

[@randall96]

Would this cause a low pressure light? I cleaned mine up recently

[@bigbore400]

what about on a modern Diesel engine. I have one hose from the top of the engine going to the intake hose pre turbo. Are there any other pcv hoses on my system.

[@soufbel3455]

This PCV acts like a check valve or it allows air to pass in both directions? 👍👍👍

[@passionplanet4471]

Great demonstration😊thanks for the advice and tips

[@reiannaidoo]

I just love your videos. Keep up the good work, you're doing so well.

[@tubetime39]

I blow through each end of my valve and air easily flows both ways. It does not really close. You mentioned the valve will close or nearly close at idle. Why does this have to happen and if it does not close, does that create a problem ? I got the impression that a valve is not even necessary, just a hose. Does the valve open only so far at different engine speeds ? And would this be to reduce too flow and too much oil from entering the intake/throttle body ? Seems to be a spring in mine, what's it's purpose, to control how much the valve opens I take it ? Seems to be an excess amount of oil in my valve also. Thank You Anyone !

[@peterscotney1]

Simple and informative , excellent vid

[@kasp3rrr457]

can we close this pcv valve, and on admission before and after, if we add OCT on air admission

[@صيانةالسياراتعلموخبرة]

what will happen if the breather hose get clogged

[@tyronewalker5764]

Well done sir.

[@myRatchets]

+Tyrone Walker ty ty

[@tyronewalker5764]

Just pulled out mine from my 4.7 V8 Dodge Dakota. What a mess, full of oil and gunk!

[@shamwaymoonyos9578]

Yep same. Liked and subscribed :).

[@greenhammer1148]

is the breather tube a one way tube only?

[@HussainAAlaaraji112]

What if I found a huge amount of oil in the breather tube ... what is causing this ?

[@AWIERD1]

Hussain A. Alaaraji Having a super/turbo charger could cause alot of oil in the breather tube.

[@joesmith-fi1sx]

hi there, i have a 2000 dodge dakota v6 , my pcv valve is hosed to the rear airbox on top of the throttle body , I have seen other same engine dakotas where it is hosed to a port on the side of the manifold , on my engine that port is capped of with a rubber cap . I am confused and am planning on replacing the valve and want to do it right .

[@pidgeiam4979]

Great explanation. Very clear and understandable. Thanks very much, Pidge.

[@myRatchets]

+PiDGE IAM np, glad you liked the video. cheers

[@joyace9674]

Does the PCV valve have something to do with the code p0171 I took it off to clean the sensor intake and put it back on but the engine light still goes on with that same code number I saw your video and maybe I have to change that part not sure but I will try it and see I have a corolla 2,06

[@hiramcastillo7137]

Perfect...no body shows it better bless

[@cRiSpIn3F]

Ok I have 73 el Camino with 350 and every time I hook up the pcv valve it runs high in idle than when I plug it it runs fine. (What up with the pcv valve when I test it it make a hissing noise)

[@chrismadison620]

Can the oil end up in your exsaust cause that's the problem I'm having and I have a bad pcv valve.

[@myRatchets]

Yes a bad pcv valve can cause oil consumption (engine burning oil) and some smoke out the tail pipe. If you have actual engine oil in your exhaust make sure you didnt over fill your engine with engine oil. GL

[@quickchrome2012]

Does a 03 Sierra 1500 is open from factory?. The stock one is just pcv valve with nothing inside just a big hole and a smaller hole. Nothing inside the pcv valve to rattle. The new one is the same.

[@joegomez478]

What the difference between a pvc valve with a ball inside it as apposed to one without a ball inside it?

[@adammeke1896]

Plz how much pressure in crankcase for Chevrolet Cruze 2012 1800 cc?

[@JuanMorkan]

Is two pcv valves overkill? One on each valve cover.

[@abdalqadr1]

Smart man thanks for you from Iraq

[@hassanwardeh3458]

. Well done sir , Good explanation, diagram and demonstration

[@dogsbyfire]

Very nice drawing. Thank you!

[@ortega181956]

great info. job well done explaining the pvc valve operation and texting. Thanks

[@denospyridon3126]

Thanks for explaining plus showing a Toyota Camry cause I have a 2004 2.4 4 cylinder and changed mine and now the car gets what it was originally intended to get the mileage 24 city and 30 hyw. Thanks

[@mrsassypants8218]

Where is this located on a 2015 Mazda 3 skyactv itouring?

[@tradmanmike3360]

GREAT VIDEO! GREAT NARRATIVE WORK. NEW SUB. THUMBS UP!!!

[@buckwild6587]

Ok so 93 chevy k1500 with a 5.7. I was GOING to put a valve cover breather in it but ive got a pcv valve. So does that mean i dont need it?