This video may have helped me solve my '96 Olds 88 rough idle problem. I replaced plugs, wires, cleaned fuel injectors to no avail. But after viewing this video I hunted down the valve (it's hidden under the MAP sensor) and replaced it. The valve did not move freely. Total cost $3.21! Idle is better and I'm hoping oil consumption will improve too. Thanks!

Cheap, and easy to change. People don't talk about it as a maintenance item enough. 👍

One of the first thing a young car guy learns about is how a bad pcv can muck things up and cause problems that aren't always easily discernible. Thank you for the full and clear explanation. Always glad to learn new things from your channel.

Thank you for the video and great explanation. My husbands truck hasn’t been sounding right on the highway. I drove it yesterday and the “low oil pressure” light came on and then went right back off. I decided to check the oil- ZERO oil on the dipstick. Did some research and tested the PCV valve, zero suction. Waiting on hubby to bring me the part- I’m just hoping no damage occurred. I had no previous knowledge that something so simple could prevent major issues

Gotta love your engine videos like this one, there's nothing better than your clear thinking explanations.

Did not know about the dipstick popping out. Mines used to be doing that. Had a major oil leak also. I definitely learned something new just now

I very much enjoyed your video on the PCV valve; it explained how the valve functions in regular everyday terms without getting caught up in the jargon. Nice, simple and it made sense to someone who is not a motorhead. Well done!

Ive been lucky enough on my vehicles over the years, the PCV valves are easily accessible. When i do my oil changes, i remove the valve and spray a little carb cleaner in there to flush any residue out. Havent had an issue with one yet... Great explanation of the PCV system.

Great video! My 04 Silverado 1500 z71 had a PCV get stuck open. It was pulling oil though it into the intake at around 2qts per oil change. Once I finally learned about it, I found GM revised the valve cover due to the original design causing major failures. I wish I knew about the PCV system earlier.

You're a car genius and very good at teaching and explaining how cars work!!! I really appreciate you. Keep up the good work!👍

Thank you so much for the explanation of the PCV valve, I usually do all of my own work but my wife’s car is still under warranty so I let a garage (warranty approved garage) work on the car idling bad at stop and stalling a little while going down the road. They told me it was the left side valve cover gasket letting oil into the intake. I had to see if this was correct. Through your video you explained how this can happen. They should have just told me the PCV valve though. I really like your page and very detailed for us DIY’s out here.

Great Video as always!! The only thing is try not to use gloves when checking the vacuum on the pcv. I had a small piece tear off and suck through my pcv valve. The force was strong in my truck!!

Replaced on 70s 302 Ford pickup. Fram. Ran lean backfired up carb. Always use factory part. Genuine Ford valve fixed.

Nice tutorial. If I may add: I was thought that the main reason for the spring operated valve inside the unit was to prevent flames from backfired carburetor to go back and ignite the air fuel mixture in the crankcase. In old engines with carburetors, a backfire flame can travel through intake manifold through the hose back to the valve cover and down to the oil pan area. Thus, the name Positive Crankcase Ventilation valve. Otherwise a one-way valve. Before PCV valves on engine, there was a draft tube that vented the unburn air and fuel mixture to the atmosphere. This produced smog. With fuel injector systems on cars, there is very little if any chance of backfire. There is still a need to remove unburned air/fuel mixture from the crankcase. A small spray of carb cleaner can go a long way to keep the valve working.

I got a callapsed PCV hose on my 99 Ford Focus, I got the car on the cheap and the garage had just replaced the rocker cover gaskets and the rocker seals. I then had to replace both main seals and the sump gasket has now sprung a leak... This hose has essentially required me to replace all the main seals... It makes sense to spend £50 to replace everything PVC related once in a while!!

Just found your channel. My only complaint is that I didn't find it sooner! Rock on man!!

good explanation of the PCV and a very important part, this to reduce pressure inside your engine and burning the blow by for cleaner air.

Great explanation on PCV valves. At 120,300 miles I replaced the water pump (weephole leak) and drive belt on my 2018 Civic EXT. Since Honda service were already working on that I had them replace the PCV valve as preventative maintenance. Aside from an earlier AC Condenser replacement (fully covered under Honda extended warranty), the water pump, drive belt, coolant flush was the only major work on my four-year old Civic (Total cost: $1,045.00). Currently averaging 34.1 mpg. Great car.

This is the best PCV valve instructional video I have ever watched. Good job man.

These videos are great for solving simple problems that otherwise would be by mechanic and automotive shops that would replace the $25-50 part but charge you for a pile of "OTHER" works they didn't really do.

This is great information! i have the very symptoms you mention, and its only a $10 fix- and requires no tools!!! I’m pulling no codes, but there’s gas smell in the oil, a new oil pan leak, and a new valve cover leak, and i feel like performance could improve slightly. THANK YOU! /2002 Lexus RX300

I had an issue with a 01' Firebird. I was fixing everything on it trying to figure out the issue. Went as far as a doing a complete head gasket replacement. It wasn't until I was putting everything back together that I noticed how nasty the intake manifold was. Yep it was a damn 5 dollar pcv that was causing the biggest of the issues. That said it was good to do the complete head gasket replacement as it was 160k and looked like it was starting to go. I swear it gain back a few ponies as I also polished the valves and heads.

I just went through this same thing on a '98 Ford Contour 2.0. On this one they made it where it's really difficult to get to. It is not on a valve cover it is in the crankcase, under the exhaust manifold. There's no way to get to it without removing the e manifold. The valve cover vents into air intake. Repairing both, valve was clogged, now working and the other hose from the valve cover was rotted. It still has crankcase pressure. At idle remove the oil fill cap and it feel it blow out a lot of pressure. Seals are leaking, they stopped for awhile when I repaired pvc system but pressure is back. And, as you said, vacuum only happens at idle, I can only imagine the pressure get worse above it. Told this customer it a goner.

I rebuilt my first engine by myself top to bottom in 1969 as a 14 year old. it was a 1954 272 Y-block Ford. Worked as a heavy equipment mechanic for over 31 years for a local municipality 9 years as a shop supervisor. I learned hands on rebuilding and repairing things not replacing them from old timer's who knew more than I could ever fathom learning but they taught me all they could including welding, machining and fabricating. I was a good student and a fast learner. Attended an automotive tech school for four years. Could have been a teacher. Was NAISE certified in every phase. None of my mentor's ever gave much thought to the PCV positive crankcase ventilation system even on engines that were not taken care of. In my 40 plus year career I never found a stuck or malfunctioning PCV valve or suspected one of causing a major engine or component failure. Yes compression can sneak by the rings on older engines as well as new one's and cause some blow by and slight pressurization of the crankcase however in order for that much pressurization to occur it would blow out a seal or a gasket first. I do know if a PCV valve is stuck in the open position it can suck in engine oil and burn it along with crankcase vapors through the carb base however all factory valve covers have a baffle that covers the small place where the PCV valve lives protecting it from engine oil slung up from the rocker arms. So in theory even one stuck open would not cause an excessive oil consumption issue. Aftermarket valve covers often lack that little protection for the PCV and an oil consumption issue could arise. Since a PCV has full manifold vacuum to it that can be a starting place to look for an engine performance problem such as a rough idle. No two mechanic's agree 100% 0n everything. Most agree to disagree.

Sir, your mechanic aptitude and teaching style is above all , Thanks 🙏

Yo just be careful on older cars, these get brittle over time and will crack into tiny pieces. I changed mine out and my car went from smoking to a much cleaner burn. No more smoke and it's a cheap parts. Well worth it.

On competition engines there are are breather filters on top of the valve covers to vent the pressure. The filters are there to prevent debris from entering the engine but not to obstruct the vapors coming out of the engine. These vent directly to atmosphere. It is very important to not let the vapors build up pressure in the engine as he mentioned.

Just got done reconditioning a Honda H22 with all new seals, timing components, etc. Installing into the car after it was on the road I kept noticing oil coming out of the new distributor seal, vtec solenoid gasket and cam seals - all the head seals. Replaced the PCV valve and I'm not seeing oil seepage in the day I;ve driven it thus far. Amazing what a $15 part can do...

Cleaned and sprayed out my PCV on my 2002 Yaris 87.000 miles and was easy to get to.get off and wasn't that bad/dirty but did needed to be done...preventative maintenance folks.

A few years ago I bought a Toyota Sequoia cheap because the dealer thought the engine had bad head gasket or worse. After checking things over I found the PVC totally blocked. I installed a new PVC valve and I'm still daily driving that Sequoia with no issues. Yes replace the valve, It's cheap and easy to replace on most engines.

Most overlooked simple part.

I just bought a PCV valve today and this video got recommended 😂👍

Another overlooked item is the differential breather valve that releases the pressure inside the differential if it gets plugged up it blows out the seals from your axles

thank you so much i really like the way you explain everything no wonder i have oil gasket problems

Great video,,,, On carb engines it also keeps a Lean backfire from blowing seals out of the engine by it blocking pressure to the crankcase. EFI rarely if ever backfires from a Lean mix.

This is a great vid. The symptoms matched unexplained problems on our RAV4. Turns out this is a common problem for that car. Thank you for your videos and how you demonstrate and explain. Like your style.

NOW WE KNOW HOW IMPORTANCE IS IT AFTER I REPLACED WITH A NEW VALVES ON 2021 CHEVY AND 2008 COROLLA I CAN SEE THE GAS SAVING AND MORE POWER. THANK YOU.

Probably the best PCV valve video i have seen so far. Thanks

The turbo on my 2005 GMC 2500 with a Duramax was getting filthy because the turbo was the vacuum source for the PCV, since diesels engines do not have vacuum. I changed the PCV hose routing to where the PCV hose was simply venting to the outside and I put a filter to keep debris out of the engine. It has been working fine like this, and the engine oil and turbo stays far cleaner. The engine insides are also far cleaner as well. No need to burn filthy oil vapors in the engine again constantly.

This is why predominantly they make this simple and essential part the biggest pain to get access to.

Great info! Never heard Scotty screaming about it LOL. Was worried that my engine is about to blow, because the car is old, but since it has an Ecotec engine it should be fine. Thanks again!

Very good video,this little overlooked piece of plastic and sometimes metal can really cause a lot of problems,i had this car one time and everytime i stopped at the light i could see smoke coming from my hood,not bad mind you but it was there. I could also smell a horrible oil smell (it was horrible and I'm a mechanic and shop worker,bad oil smell's dont normally bother me) and all of the sudden my car developed a few oil leaks out of nowhere,i decided it was time to start troubleshooting,i got all the way laying in my hood looking at the back of the engine with a flashlight,this valve was waaay in the back buried,the valve had popped out while i was doing some unrelated maintenance unbeknownst to me, the oil smell was coming out of the hole, the smoke was from hot oil leaving the hole and the oil leaks was from the crankcase not getting the proper ventilation which is a job this valve does,major problems over a 10 dollar part.

Omg Great Video 👍🏻 another test is to hook up a small vacuum line to the PVC and create a vacuum effect , this way you can hear and feel it working .

Very detailed video with both stuck closed and stuck open symptoms. Very nice video!

the birds sound beautiful and add a nice atmosphere to the video

I always knew to change it on a tuneup but now I know why. 👍🏽

Good job; I had forgotten the way a pcv valve system works. The new pcv valve for my Ford is only $3.99 at AutoZone.

I'm glad you touched on a subject that is rarely brought up! This is why I subscribed. Those birds need to chill out! Thank you for this video and happy wrenching!

Very informative. I got a new pcv valve as my truck is consuming oil but no smoke coming from the trail pipe. It has a bit of a rough idle every now and then so I'm thinking check valve first. Love your videos. Keep up the great work!

Wonderful explanation. At this point, the better explanation for a PCV. Thank you! Not to sound sarcastic, but I learned based on how you test them (which makes sense) I have wasted about $8-10 replacing this valve needlessly. Thankfully though, they are cheap!

I’m currently changing my engine out and while I was tearing down my old engine I heard something hit the ground and I had no idea what is was just turns out to be the exact thing you’re talking about in this video weird that it popped up in my recommendations but thank you!!!!

Went to change my wife's PCV valve a few years back, simply because of mileage. Genius Toyota put it under the intake manifold and on her car, it requires removing the whole front clip, radiator, and starter to take the manifold off. Lord help me if that thing ever actually fails. Of course on my DODGE, it's right on top of the engine...2 minute job.

Excellent video!!! Your very much appreciated!! This explains the sudden oil leak from everywhere! I just replaced the DPFE sensor last week. I can't see that it changed anything by doing so. Now I wonder if my old Ford is savable? It's like over night EVERYTHING went all to pieces on it. Literally.

This video is 2 years old, coincidentally, about 2 years ago I sold a truck because I couldn't figure out what was wrong with it. It start running rough, especially at idle with thin black smoke from exhaust. Also, that truck saw a ton of "idle time", probably about 3 to 4 hours of running in park, 5 days a week. Wish I would have found this video when it was new.

That’s a really good explanation of the pcv system -two thumbs up from me 👍 👍

Part of the scheduled maintenance on that dodge is to clean the pcv hose and orifice into the intake when you replace the pcv. On my truck the hose and orifice was clogged with sludge

Excellent as always keep them coming buddy you are one of the best.

Glad didn't wait too much longer, had to order mine in when i picked up a oil gasket for my work truck

In my opinion, if your car is 10 years old or more, does have a PCV valve and is not a pain to replace, doit. The valve costs about 5 bucks or even less, and the grommet about 3 bucks or less... just replace the valve AND the grommet and you could even restore some of that lost mileage!... (or so some utubers claim) cheers! cheers!

So I'm going to go spray a gallon of brake cleaning through mine now lol. Actually in my owners manual it says to remove the breather from the valve cover on the right side of the engine and not only spray it out with a solvent, but it instructs me to pour clean oil into it every 3,000 miles (with every oil change)

The best PCV explanation on YT

This explains why I keep have so much oil leaks in my 98 civic, after replacing several gaskets and seals!

Incredibly helpful, I have changed one on my JEEP in the past which was really easy but I seem to have the only Audi were there isn't any pcv or reference to a crankcase breather so it's a bit of a nightmare, even with a Haynes manual

I saved my 2 brothers in the same week for spending money,their xj's jeep where clogged at the pcv valve and having poblems!

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

Did anyone else have an “Ah Ha” moment just now? Lol Thank you for this Video! You have made a new subscriber

I have a Honda Pilot with a rough idle and some misfiring with a check engine light saying my catalytic converters were bad. I did a tune up with spark plugs, air filter, oil change, etc. Still had the same problems so I started cleaning sensors like intake temp sensor, MAP sensor, etc. Still had the same problems. After watching this video I decided to check the PCV valve and that was bad!!! I looked inside the intake manifold and there was pooling of engine oil and it was covered with a fine layer of oil. I took out the intake manifold to clean it and replaced the PCV valve. Now I have smooth idle, no misfiring, and the check engine light for my catalytic converter is off. The dealership just wanted to replace the cats for $3k. The problems the Pilot had was just a faulty 35 dollar PCV valve.

Excellent video and explanation. One problem innerent with the PCV is the oil move inside the valve to the intake manifold with new or old valve. I stop that with an Oil Can Catcher.

Ive watched 4 videos 2 were for painting and 2 were for taking care of your car and you make me wanna become a mechanic . I'm also 3 80 proof mixed elbow grease drinks deep so I could just be hyped up to learn lol

True..... I clean mine with pcv,egr cleaner every week as its a 10 yr old car.... after cleaning engine revs lighter and stops engine knock. I also do it once a month for my newer cars and it still makes a good difference.... modern cars have bigger clearances and causes more blowby.... so the cleaning of the pcv is important...its a simple job but makes a big difference.

Thanks for the detailed explanation on the pcv valve. My 08 enclave has had major oil consumption and smoke when I accelerate hard.

thanks so much, i just learnt how to check my PSV functionality.

RATCHET THIS THE GOOD VIDEO BUBBA. NOW I WORRY MY ORIFICE. I CHECK THE PVC PIPE.

Love your videos. Excellent work. I learned a lot from you than in my entire engineering. Thank you so much!!

I’ve had a PCV valve fail in a 1.5 ecoboost. There was a crapload of oil inside the PCV valve. It caused ringland failure in cylinder 2. Had to replace major engine components, but good thing its still under warranty.

Keep these videos coming..ur the best at xplaining ..God bless you..

I wish I could 👍 this video a thousand times.

If you lived in South Texas I would take my 1998 Ford Ranger to you. I love my little truck but have several issues with motor. Too many to list. Good video and good information.thank you for taking time to explain.👍👍👍👍👍

The shaking it to see if it rattles test isn't always accurate to see if the pcv valve is still good. Mine rattled like the new one I bought but was bad. Great video though, very informative.

Great video, thorough, clear explanation and thoughtful use of additional media tools!

That's pretty good explanation. Except you didn't address what causes the PCV to fail. For that we need to go to an old marketing and advertising slogan... People who know use Valvoline. What do they know? All oil contains paraffin wax. As that paraffin gets separated under high heat conditions it gets sucked into the upper part of the engines and is allowed to cool. Leaving the paraffin content behind. Which builds up on small components such as that little spring loaded valve. In order to stop this buildup a low paraffin content oil should be used. And there's only one of those on the market. Valvoline. Quaker State Pennzoil Castrol and most of your synthetics, are very high paraffin content oils. Most of your synthetics are almost straight paraffin. This paraffin builds up all over inside the engine including the oil passages themselves. When the PCV is stuck in the closed position, those Vapors push the oil out of the seals through least path of resistance. Which is the same principle as electronics use for flow of current. In the case of an engine, those weak seals are the ones that surround rotating components, such as the front and rear main seal of the engine. However, that paraffin will also build up on top of the Pistons. And after the detonation of the spark plug, that oil can smolder on top of the piston. So when the air fuel ratio is introduced into the combustion chamber it's can be ignited before the spark plug. This is called predetonation. Which will in turn, burn holes in the top of the Pistons thus leading to insufficient compression. Which looks like what was happening, or about to happen on those pistons in your display engine. It is literally Murphy's Law that says a $0.10 fuse will destroy a $50 relay every time. In this case your PCV valve is the $0.10 fuse. And all of the components destroyed by lack of crankcase ventilation, is your $50 relay. Literally, I $3.95 part will save you thousands in engine repair when maintained regularly. Which in most cases is anywheres from 5 to ten thousand miles. Personally, as a professional mechanic, I love it when you don't change your PCV valve. Because I'm going to charge you $75 an hour to fix all the damage it has caused. In most cases, just to take the engine out of the car, you're going to be billed 6 to 10 hours depending on the year make and model. And you have to take the engine out of the car, or the transmission, to replace that rear main seal. There's no shortcut around it. And there is nothing on the Shelf at AutoZone that is going to stop that rear seal from leaking. There are no pills in the automotive industry. There's only one way to fix a problem. The right way the first time. You need to make a decision. Do you want to change the $3.95 PCV valve? Or do you want me taking your engine out of your car, putting $500 in seals in it, and putting it back in for around $2,000? Did you notice, he did not hook up a computer to find this problem? That's because you can't. In fact, that least path of resistance thing that I said earlier... Could be out the side of a knock sensor or an oil pressure sensor or an oil level sensor. So now we're not just talking about seals... Now we're talking about cheap China sensors. A 5-cent diode... That I'm going to charge you upwards of a hundred and fifty bucks to replace. Cam position sensors, crank position sensors... Oil is a corrosive on plastic. And it wipes those out too. As a mechanic the best advice I can give you is, find someone that you can trust to help you with the maintenance of your vehicle. Make sure that they are knowledgeable and at least State Certified. Keep in mind that mechanics solve these problems every day. Where is your plumber painter electrician construction friend... May have never solved this problem at all.

Thx for this vid our classic was white smoking and leaking. After this vid we realized it was the coolant leaking.

Thank you Ratchets & Wrenches! I had a 2001 Ford Taurus and the PCV Valve went bad. Replaced it, and it stopped stalling at lights, misfiring, and it drove a hell of a lot better too.

I really love how you explain everything. Even an old lady like me gets it!!!!!

So, we take funky oil filled vapor and feed them into a nice clean Throttle Body, Great Design !

Love this video I found it super helpful. You are easy on the eyes too. 😊

I like your videos as they are always informative, interesting and to the point so I always come away with having learned something.

Great Vid as always bro Thank you!! If PCV Is stuck opened or closed would that also change fuel trim??

I new the little bugger was important but not that important thanks for the info

Perfect explanation of the PCV valve and it's purpose.

Thanks for the video - very helpful. Could you do a follow-up on the EGR/crankcase ventilation systems of more recent vehicles that have no PCV valve, but which do have a PCV tube and an EGR system (with solenoids, etc.). For example, I have a 2010 Equinox with a direct injection gasoline 2.4L engine; as a group these engines suffer from excessive oil use, carbon build up on the intake valves and in the intake manifold caused by high internal crankcase pressures and blow-by; many of these engines will blow the rear oil seals because of the high pressure. While there are supposed to be extended warranties on the affected vehicles, this extended warranty coverage is almost always denied, because the affected vehicle is not on some pre-selected list created by GM. This comment is not about GM - it is simply a request that you show the average owner of such a vehicle what she or he can do to deal with the problem, whether it is adding a catch can to remove and store the excess oil, cleaning or enlarging the PCV hole in the intake manifold, adding a vent tube or an old fashioned PCV valve to reduce blow-by pressure, or something else. A lot of modern car owners have this problem, and there must be a simple, relatively inexpensive cure which doesn’t screw up the electronic fuel and air flow controls on the modern engine. Thanks for your videos and for your consideration of this request.

I run my PVC hose into a catch can - works fin intact improves performance, rather than having blow by being burned up..

One of the best in youtube.thanks a lot for a very helpful videos.

A PCV clog caused oil to go up my dipstick tube, which caused me to run low on oil despite regularly checking the dipstick. It doesn't look like there was any terminal damage but a few thousand miles longer and I would've probably destroyed my crankshaft journals. This part isn't talked about often enough. Its often cheap and easy to replace and the consequences of its failure can be devastating - so it should really be checked regularly.

Is it just good to replace it every so often even if you don’t have any symptoms ?

*Guy, while the PCV valve has been engineered into the system, I invite you to try to simply plug the PCV valve. This information is inaccurate, as you don't even MENTION the Breather Hose! That's where the blow-by will be exiting. I've plugged this valve THOUSANDS of times with ZERO negative events. In fact, I've had so many POSITIVE reports you would be AMAZED!*

I replaced it with a brand new one and installed a oil catch can. It work very well

Your demo will be soved my problem ... Thanx & Rgds...

Can you make a video on oil catch cans/ remote breathers for the PCV system especially for gdi engines? Thanks Ratchets

Good evening family and thanks for the valuable information and for your time 👍🏼 👍🏼🙏