The PCV on this engine "is meant to apply vacuum to the crankcase" when not operating in boost. This is to improve sealing at all seals, rings, and valve stems. When not in boost, the PCV routes crankcase vapors from the PCV to the inlet manifold; via the corrugated tube. When boost 'is' present, a check or one-way valve in the PCV (where the manifold tube connects to the PCV) shuts to contain boost in the manifold. The PCV's large diaphragm then opens to evacuate crankcase vapors, for recycling, via a different route. This → When the large diaphragm opens, a second check valve in the PCV opens, to allow vapors to escape through the rocker/valve cover, through the rear vent tube, and into the turbo inlet; for vapors to take the long way around to be recycled. There are two distinct designs of PCV on this engine. You may notice the rear vent tube comes two ways; one with no valve in the upper opening, meant to be paired with the Rev.-R PCV. And another with a valve set in black plastic at the upper opening of the rear vent tube; meant to be paired with the Rev.-P PCV. However...the Rev.-R PCV will work with either rear vent tube...where the Rev.-P only works properly with the valved rear vent tube.
its the other way around, if you crankcase is under high vacuum its bc the diaphram is torn and the spring is keeping the valve open allowing full manifold vacuum in the crankcase.
This person, MiniH0p, is correct. This much vacuum, where you engine instantly chokes and stops running, is proof that the valve is stuck in the OPEN position, causing rough idle, misfires and oil leaks (eventually) from having too much exhaust gas going back into the engine at idle. I know this because of what others have said about this issue online. Alternatively, you can test this by pinching off the hose that goes to the PCV valve and see that the rough idle goes away instantly. One UA-camr does that test here: ua-cam.com/video/ePfpOM5-S6k/v-deo.html
Is this happen on Naturallt Aspirated engine too? Mine has mist of oil on its engine cover. Have replace the oil cap. No oil level problem. But there still oil mist on it.
I am so confused. Mine is 2011 2.0 tfsi...when removing the cap,there's absolutely no difference...is it means that my pcv is good or bad?please someone help..
My 2015 jetta also increased air pressure when I open oil lit and I change my PVC valve but it’s still same nothing changes . Please suggest me something .
I don't know much about turbos, but that seems like a tremendous crankcase vacuum for a car that is idling. Aren't you worried about blowing out seals? In an older video by Southmainauto, he shows an older VW with that level of vacuum and lean codes. After replacing the PCV the crankcase vacuum while idling is significantly better than shown here.
Can you confirm if this method also works on a 1.8T 20v engine? Mine's burning lots of oil (168k miles. Burns 1 qt every 1200 miles, new turbo, valve seals been replaced 4 years ago. If i take the dipstick or the fill cap, engine keeps running with no problems. Thanks!
@@discy12345 Nope. But last week did a compression test, and one cylinder is down in pressure. I'm gonna take the head out, check valve guides and seals and look for any other damages.
@@khodayesiasat1550 Hi, thanks for the reply. In my case not using cheap oil, Shell Helix HX8 Ultra for VAG specs. From all the "fake fully synthetic" oils, it's one of the best here.
Have you found the reason of eating oil? I have similar problem and if i go with high rpms (4-6k) cloud of blue smoke appears and even if i stop and idle it makes a blue cloud for like a minute
So I took off my oil cap and my cars engine started running rough and my rpm gauge was increasing. Could this be a bad pcv valve? I got the code p0507 “RPM Higher Than Expected”
bad pcv valve. check on the pcv valve if it is sucking or pushing air - easiest way to tell if diaphragm is faulty or not. I did mine on my Audi b8 A4, just replaced the diaphragm and spring etc, not the entire enclosed pcv valve, quite a bastard to do as well.
@@SparcoVRS I checked mine, it’s vacuuming alright so I don’t need to change my pcv. Gonna clean the maf sensor this weekend. I have the code P2177 on a A4b8. Next step after the maf im going to use the LiquiMoly fuel injector cleaner. What code do you have?
@@NhatNguyen-xs7kl I dont have any fault code. I have slight problem with revs dropping low and bouncing a little bit when coming to a stop. I thought that maybe it has something to do with potentially faulty pcv valve. I hope you solve your problem.
@@SparcoVRS Good to know. I did, I clean the MAF sensor with MAF cleaner and that solves my p2177 problem. Pcv was fine and I made sure all the hose connections was tight.
You are wrong! Make better research. New German engines from 2010 above are designed to have a strong vacuum to protect parts wearing. Vaccum is good , blowing out is bad! Take a better look on forums and maybe try on new cars and see that all of them have this. European/German cars. If your car is 2016 above then will have a strong vaccum
@@Dark_Xaynehi, just replaced mine on 6c polo gti, runs alot better now,, mine now has strong vacuum, are you sure it's supposed to be like that as I'm a little worried about it.. when removing oil fill cap at idle it has strong vacuum and runs funny until I put cap back on,, but all is fine when closed,
The PCV on this engine "is meant to apply vacuum to the crankcase" when not operating in boost. This is to improve sealing at all seals, rings, and valve stems. When not in boost, the PCV routes crankcase vapors from the PCV to the inlet manifold; via the corrugated tube. When boost 'is' present, a check or one-way valve in the PCV (where the manifold tube connects to the PCV) shuts to contain boost in the manifold. The PCV's large diaphragm then opens to evacuate crankcase vapors, for recycling, via a different route. This → When the large diaphragm opens, a second check valve in the PCV opens, to allow vapors to escape through the rocker/valve cover, through the rear vent tube, and into the turbo inlet; for vapors to take the long way around to be recycled. There are two distinct designs of PCV on this engine. You may notice the rear vent tube comes two ways; one with no valve in the upper opening, meant to be paired with the Rev.-R PCV. And another with a valve set in black plastic at the upper opening of the rear vent tube; meant to be paired with the Rev.-P PCV. However...the Rev.-R PCV will work with either rear vent tube...where the Rev.-P only works properly with the valved rear vent tube.
its the other way around, if you crankcase is under high vacuum its bc the diaphram is torn and the spring is keeping the valve open allowing full manifold vacuum in the crankcase.
This person, MiniH0p, is correct. This much vacuum, where you engine instantly chokes and stops running, is proof that the valve is stuck in the OPEN position, causing rough idle, misfires and oil leaks (eventually) from having too much exhaust gas going back into the engine at idle. I know this because of what others have said about this issue online. Alternatively, you can test this by pinching off the hose that goes to the PCV valve and see that the rough idle goes away instantly. One UA-camr does that test here: ua-cam.com/video/ePfpOM5-S6k/v-deo.html
My rs5 has 2 tho. Do I just do one at a time to see if one is possibly bad? If the car stays on when remove cover, that means it's bad?
Is this happen on Naturallt Aspirated engine too?
Mine has mist of oil on its engine cover. Have replace the oil cap. No oil level problem. But there still oil mist on it.
Is this the same for Audi b8 s? I have a P2177 code, system running too lean
It's the opposite mate, If you're engine runs like that or if there's suction you're pcv valve is open due to a tear or cracked
My car does this but check the pcv valve no crack or tear
@enamullahmalyar9009 Check your pcv hosepipe going to the air manifold. Sometimes they get stuck or rubber gets soft
@@luiscfc86Can you check if i have the same issue on my audi tt? I have posted a video on my channel.
True , he dont know what hes recording 😅
I am so confused. Mine is 2011 2.0 tfsi...when removing the cap,there's absolutely no difference...is it means that my pcv is good or bad?please someone help..
Lol, I was just searching here because my engine was doing the same thing when I loosen the oil cap 🙂 luckily its by design 😀
What do you do if you have this same issue mine doesn’t start with oil cap on only starts without oil vedy weird
My 2015 jetta also increased air pressure when I open oil lit and I change my PVC valve but it’s still same nothing changes . Please suggest me something .
Is it the same on the TDI?
its depends how suck air if suck so strong and hard take off oil cup then PCV bad if just you take off oil cap without pressure then PCV good .
Thank you. Very useful
I don't know much about turbos, but that seems like a tremendous crankcase vacuum for a car that is idling. Aren't you worried about blowing out seals? In an older video by Southmainauto, he shows an older VW with that level of vacuum and lean codes. After replacing the PCV the crankcase vacuum while idling is significantly better than shown here.
Blowing out seals.... with a vacuum? That's not how that works.
Can a faulty pcv valve cause a false misfire engine management code. Or would the misfire be genuine?
possible
Yes it can
Can you confirm if this method also works on a 1.8T 20v engine? Mine's burning lots of oil (168k miles. Burns 1 qt every 1200 miles, new turbo, valve seals been replaced 4 years ago. If i take the dipstick or the fill cap, engine keeps running with no problems. Thanks!
Did you find out? Same issue here.
@@discy12345 Nope. But last week did a compression test, and one cylinder is down in pressure. I'm gonna take the head out, check valve guides and seals and look for any other damages.
hi, never use cheap oil, it burns like petrol
@@khodayesiasat1550 Hi, thanks for the reply. In my case not using cheap oil, Shell Helix HX8 Ultra for VAG specs. From all the "fake fully synthetic" oils, it's one of the best here.
Have you found the reason of eating oil? I have similar problem and if i go with high rpms (4-6k) cloud of blue smoke appears and even if i stop and idle it makes a blue cloud for like a minute
So I took off my oil cap and my cars engine started running rough and my rpm gauge was increasing. Could this be a bad pcv valve? I got the code p0507 “RPM Higher Than Expected”
Did you have the code after taking the cap off or before taking the cap off?
So I did this with my s3 8v 2015
I took my dipstick out, my revs went up. All sounded normal but revs raised
This normal?
I’ve done this on my golf gti mk7 and mine raised put it back in and it stumbled to almost stalling
Could be normal, if the engine doesnt have a maf sensor and is map sensor controlled a vacuum leak will cause rpm to rise
What if you take the oil cap off and there s no vacuum
Then it's got a bad valve? 💀
What happens if I take off the oil cap and nothing changes?
bad pcv valve. check on the pcv valve if it is sucking or pushing air - easiest way to tell if diaphragm is faulty or not. I did mine on my Audi b8 A4, just replaced the diaphragm and spring etc, not the entire enclosed pcv valve, quite a bastard to do as well.
2.0 tfsi 2011...same..absolutely no difference when removing the cap..high oil consumption...
My car runs rough it acts like it wanna cut off
Hi. should the PCV be hissing. is this normal ?
i think that means it needs replacing mate
When I take off oil cap engine starts to rev up to 2000 rpm. Is this normal or not? Thanks
You ever figure it out? Did you change your pcv?
@@NhatNguyen-xs7kl I changed my pcv valve and it's doing the same with a new one
@@SparcoVRS I checked mine, it’s vacuuming alright so I don’t need to change my pcv. Gonna clean the maf sensor this weekend. I have the code P2177 on a A4b8. Next step after the maf im going to use the LiquiMoly fuel injector cleaner. What code do you have?
@@NhatNguyen-xs7kl I dont have any fault code. I have slight problem with revs dropping low and bouncing a little bit when coming to a stop. I thought that maybe it has something to do with potentially faulty pcv valve. I hope you solve your problem.
@@SparcoVRS Good to know. I did, I clean the MAF sensor with MAF cleaner and that solves my p2177 problem. Pcv was fine and I made sure all the hose connections was tight.
My can runs like ot wanna stall idk sat for 6 months may just need a tune up
did it fix your problem?
I swear down this is wrong, no way should your engine be creating that much vacuum inside
Nope my Audi A4 does the same thing it’s the vacuum he’s right.
@@victordelgado1453 all other videos and I’ve literally just changed my pcv and it doesn’t do this lol
You are wrong! Make better research. New German engines from 2010 above are designed to have a strong vacuum to protect parts wearing. Vaccum is good , blowing out is bad! Take a better look on forums and maybe try on new cars and see that all of them have this. European/German cars. If your car is 2016 above then will have a strong vaccum
@@Dark_Xayne this is a 2005 a4 not a newer car!
@@Dark_Xaynehi, just replaced mine on 6c polo gti, runs alot better now,, mine now has strong vacuum, are you sure it's supposed to be like that as I'm a little worried about it.. when removing oil fill cap at idle it has strong vacuum and runs funny until I put cap back on,, but all is fine when closed,