# Ramifications of Removing Rear PCV Check Valve After BSH Catch Can Install



## Thy_Harrowing (Dec 7, 2014)

Title pretty much says it all. I have the much loathed putting noise from my rear pcv check valve after installing the BSH comp catch can. I'd very much like to remove the valve to eliminate the noise. I found a boatload of threads about removing the valve but none that really delved into the ramifications of doing so (besides stopping the noise). I'd like it if anyone can elaborate... For some reason I can't shake a bad feeling about the idea of having no check valves.


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## 2006_A3_2.0T (Jan 11, 2013)

opcorn:


I sense there won't be a clear answer but Iam interested on doing this too.

My oil consumption is insane on daily conmute, but on weekends ispirited driving it gets no worse, I highly suspect the oil consumption thing has something to do when at idle, under vacuum. I wanna remove the check valve aswell but I dunno if there are cons on doing this, like if it will have an insane flow of oil to the IC? 
and with the oem PCV this oil will "skip" the turbo and go directly to the intake manifold when on vacuum? so much questions.


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## Thy_Harrowing (Dec 7, 2014)

To the experts:

Well today happened to be a free day and I got a little impatient so I went ahead and removed the check valve despite my apprehension at first. I decided to just go for it because most of what I could find seemed to suggest it really isn't a problem to remove it given how the catch can system alters the PCV flow. My check valve turned out to be one of the newer revisions and was more difficult to remove than the older ones are supposed to be but it still wasn't that bad. I made sure I thoroughly cleaned and dried that hose out before reinstalling. When I reinstalled I decided to forgo the heat-shield that was there originally because it didn't seem to be big enough or position well enough to be serving any seriously important purpose and every attempt to install it with the hose was absolutely exacerbating. So I said screw it and just screwed the hose straight in. At one point when I couldn't see too clearly down there I thought I heard something fall down into the subframe and the only thing is could have possibly been was one of those black (I think) metal gaskets that go between the hose and the top of the turbo but I couldn't find it anywhere with my long magnetic wand so I'm pretty sure that was my imagination (but if it was then I never had a gasket to begin with).

So why am I adding all this detail?

Well because there is only one thing I noticed after the install and running the car that I am a bit concerned about. There is the distinct smell of very, very hot metal (exactly like an overheated hairdryer) coming from right down there. I am absolutely certain that nothing was in that hose so the turbo should be fine. Logically the only thing I can think of is regarding my neglect to install the small heatshield. But all it was shielding was heat from that metallic-ish sheathing that goes over the hose running next to the breather tube. I really doubt that is the source of the smell. I'm basically at a loss. It is pretty pungent and I'm a bit concerned if something metal is getting that friggin hot. On second thought, I guess it could also be caused if that black gasket I read about that I thought was metal was actually not metal, in which case I bet the hot metal smell is the metal hose directly joined to the top of the turbo. Anyone wanna clarify what that gasket is made of? I am anal about checking my car so I would have smelt it before if it was going on earlier. There is no doubt it started after I finished this work. So if anyone can chime in feel free...


To 2006_A3_2.0T: 

If you do decide to do it keep in mind that the hose is fairly difficult to get at unless you have the right stuff. Fortunately a small 1/4in ratchet and a 20in extension made it possible for me to use the ratchet completely in the open without stuff getting in the way of its motion. You'll need a 5mm hex bit to attach to the extension. That's basically it unless you have the one-time use hose clamps at the top of the hose. I lucked out and had one of the clamps you can adjust with a 7mm socket. If I can help in any other way let me know. If you have one of the updated breather hoses (I think the last 4 of the part # is 215B) I can tell you how I got the valve out. I have not seen any guides for that valve version.

Also I gotta say, unless that smell I mentioned turns out to be a real issue I don't regret removing that valve one bit. My car finally sounds and idles like it used to. I literally think my car just sounds happier without that valve, and it isn't just because the putting is gone. The whole quality of the idle is far, far better. Also, could be wishful thinking but I'm pretty damn sure that I got a little bit of increased throttle response. I'm usually pretty in-tune with that stuff.

Last thought... depending on your climate you may consider removing your catch can in winter time which means you will want to have a backup breather hose WITH the check valve to swap whenever your catch can is off. Just something to keep in mind...


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## 2006_A3_2.0T (Jan 11, 2013)

nice thanks for all the info.

I don't run the CC but the block off plate. This apply to it asweel right? gonna remove the check valve soon when I have the time.


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## ROH ECHT (Dec 9, 2010)

You should do the check valve delete if running a catch can or block off plate...removing the check valve messes with the oem pcv functioning properly if the pcv is the revision with the boost check valve removed...because it was moved to the rear tube.


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## Thy_Harrowing (Dec 7, 2014)

+1. Glad you asked before doing the delete! 2006_A3_2.0T

ROH ECHT: Have any input on my little situation described above?


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## mattA3 (Feb 24, 2010)

I have been running no check calve for years in conjunction with Catch Can. No Problems. I would be concerned about not running the heat shield. I know its a pain in the ass to put back together but it has a purpose and may be why you smell something burning.


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## ROH ECHT (Dec 9, 2010)

Thy_Harrowing said:


> +1. Glad you asked before doing the delete! 2006_A3_2.0T
> 
> ROH ECHT: Have any input on my little situation described above?


Yes, I have input...hot metal wouldn't have a smell. I believe you lost track of a plastic bit dropping against something hot. If true...it should go away when burnt to a crisp.
I hope, for your sake, you got a good seal where you left out the alloy gasket between the tube and turbo inlet. You'da had better luck with the gasket if you hammered it flat about the two small holes when it was loose. There are small tabs about the edges of the two small holes that hold onto the two screws to aid in the install, but, again, they have to be flat so those tabs will hold onto the screws. If it leaks without the gasket...you just won't get properly metered air. The ECU will go off the data from the MAF which will report less intake air.


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## Thy_Harrowing (Dec 7, 2014)

Doesn't smell like any burnt plastic I ever smelled before. Smells like an overheating hair dryer or clothing iron and I always thought that was the metal but hey maybe it is the plastic. However, supporting your theory is the fact that today after a drive to work I could not pick up the smell anymore so maybe it was something that got burnt up. I sure hope it didn't cause any damage beforehand. 

As far as the seal is concerned I made sure the seal was good as far as I could tell and I didn't notice any abnormalities whilst driving nor did I get any CEL so the ECU can't have picked up anything too out of wack. On that note, guess what I found!? I found the gasket. I couldn't for the life of me find it while I was searching and I searched so hard I thought I couldn't have been there in the first place but I was driving to work today and went over a good bump and heard it fall from somewhere onto something else... that something else turned out to be my control arm. The control arm cradled it pretty well so it was there when I pulled over and I retrieved it. Putting it back in tomorrow, with the heatshield too, since the gasket tabs will make it easier to install the whole assembly. I'll be glad to put this whole thing behind me. 

I just hope whatever was burning wasn't/isn't going to be an issue.....


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## 2006_A3_2.0T (Jan 11, 2013)

glad everything turned OK :thumbup:

I have a few questions to decide go tackle this:

In the end removing the check valve makes the putting sound disappear only? Can you feel another benefit from this? :beer:


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## Thy_Harrowing (Dec 7, 2014)

I never just ran the block off plate, I went straight to the can so perhaps our situations are a bit different. I don't know about your block off, but when I installed my can not only did the putting sound start but I also noticed a bit of a poorer idle quality. I was willing to put up with it given the benefits of the CC but I can say that removing the check valve definitely returned it to that lovely smooth quiet idle it used to have. Once I turned my car on, got distracted and second-guessed whether I turned it on, it's that quiet. That'd never happen when that chech valve was still in there. 

Also, this may have been the wishful thinking effect but I'm pretty sure my throttle response improved a touch when I removed it. I'm pretty in-tune with my car so I usually notice stuff like that. I'm not saying I got more power, Im just saying when I step on the pedal the car reacts quicker... That's throttle response just in case you hadn't heard the term, but you probably have.


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## ROH ECHT (Dec 9, 2010)

Sounds like you have had some luck and all looks to be going in a positive direction. Good to see. :thumbup:


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## Thy_Harrowing (Dec 7, 2014)

Yeah, the tabs on that gasket made it 10x easier to put it all together properly. Thanks for the input earlier btw.


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## ROH ECHT (Dec 9, 2010)

Thy_Harrowing said:


> Yeah, the tabs on that gasket made it 10x easier to put it all together properly. Thanks for the input earlier btw.


I was helping put my motor back together and my tech, having had lots of experience with the rear tube due to the recall, just bent the ends of the gasket a bit(about 30 to 45 degrees) right about at the center of the holes at each end...instead of flattening those tiny tabs. So any future readers can try that as well.


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## McVee (Nov 20, 2009)

ROH ECHT said:


> You can do the check valve delete only if running a catch can or block off plate...removing the check valve will not work with the oem pcv.


Are you sure about this? I've read of people doing the check valve delete purely to remove the putting sound when the engine first drops to idle.
On my mk6 golf r it's a single pop sound. Kind of odd. Also while driving it gurgles a bit out the intake which I don't mind as much.


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## Thy_Harrowing (Dec 7, 2014)

McVee said:


> Are you sure about this? I've read of people doing the check valve delete purely to remove the putting sound when the engine first drops to idle.
> On my mk6 golf r it's a single pop sound. Kind of odd. Also while driving it gurgles a bit out the intake which I don't mind as much.


Never thought I'd see this thread come back lol. This thread was from back when I was still learning (ROH was a good mentor) and in the last 4 years not only has the car evolved into something drastically different then factory (including the whole PCV system) but I've learned just about everything there is to know about this engine from a design/function standpoint so I can confidently say that, yes, ROH was correct in the statement you asked about. You can completely safely delete the rear PCV check valve WITH a catch can or front PCV block-off plate but you do NOT want to delete the rear PCV check valve if you have retained the factory front PCV. If you want I can provide a full explanation of how the PCV system works as well as diagrams/reading material to help visualize and support why that is the case.


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## ROH ECHT (Dec 9, 2010)

McVee said:


> Are you sure about this? I've read of people doing the check valve delete purely to remove the putting sound when the engine first drops to idle.
> On my mk6 golf r it's a single pop sound. Kind of odd. Also while driving it gurgles a bit out the intake which I don't mind as much.


Yes, The oem pcv needs both check valves to allow the pressure control valve, or diaphragm, to operate correctly.

If the oem pcv is the later revision without the boost side check valve, and you remove the rear tube check valve...then, if there are any problems with the system...under vacuum, the intake manifold can suck air from the turbo inlet, through the valve/rocker cover, and into the intake manifold because the rear tube check valve shuts under vacuum.

Here, circled in white, is the older style boost side check valve, of the oem pcv, that is not yet moved to the rear tube. It is the white disc seal and its post goes through the tiny hole:



So again, semi-circled in red is the boost side check valve that was moved to the rear tube. The pressure control valve(or diaphragm) is sort of a redirecting valve and needs the check valves operating so it can do its job. So in vacuum, and there is no "boost side/rear tube" check valve, the intake is free to draw in air into the manifold...bypassing the turbo inlet and throttle body:



Does any of this help?


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## McVee (Nov 20, 2009)

Ah damn, so to remove this sound I need to first install a catch can?

The sound on my car at idle is actually only just as the needle drops from accelerating and then hits idle, there is a once off tap/putting noise.

When driving at low throttle, it putters/gurgles at probably 2-3000rpm, and is quite obvious when in a carpark. 
If you're not paying attention, sometimes is sounds like there's an aeroplane in the distance rumbling away.

I've actually purchased a new factory (front) PCV valve just incase my current one has some issues.
BTW for me I noticed this just after installing my Volant intake.


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## ROH ECHT (Dec 9, 2010)

McVee said:


> Ah damn, so to remove this sound I need to first install a catch can?
> 
> The sound on my car at idle is actually only just as the needle drops from accelerating and then hits idle, there is a once off tap/putting noise.
> 
> ...


 Catch-can or pcv delete works because both require the elimination of the pcv to intake manifold tube...and then the rear tube can be valveless. 

Actually, you do not even need a pcv delete or CC if wanting to remove the rear tube's check valve. *You could simply modify the oem pcv* if it doesn't have the check valve in the area I circled above with a white circle and has the check valve in the rear tube instead. Remove the "pcv to intake manifold" tube and cap both ports with reinforced silicone caps...just get the correct size( https://hpsperformanceproducts.com/...LMRgKQ62JSi3ECibySUxiAZOOKNJRi9BoCH4QQAvD_BwE ). Then, carefully pop off the control valve/diaphragm cap. *You need to be careful removing the diaphragm cap so you do not crack it*. The center plug of the orange'ish diaphragm, that plugs the small hole, can be cut out so to not be allowed to plug the hole any longer. Cut around the center but only through the thin portion of the diaphragm and also remove the spring. *You need to leave the outer perimeter/ring of the diaphragm intact* because it is what seals the cap to the pcv. With the center of the diaphragm cut, the spring removed, you can replace the outer perimeter of the diaphragm and replace the cap. Then you basically have a pcv delete with no intake mani tube and no rear check valve. My vid...look at 3:30 so to see its construction. https://www.youtube.com/watch?v=jfaD4nrut90

The putter sound may likely be fixed with a true oem pcv. But the sound may be the rear tube's check valve itself failing. The sound is from either the control valve is damaged or rear check valve is not sealing when under vacuum. If a new pcv doesn't fix it, then it may be the rear tube check valve is fouled and not sealing. 

You can go with different set-ups. Go with a dual valved pcv and open rear tube. Or refresh yours as is. Modify the oem pcv as I described above w/open rear tube. Or go pcv delete or catch-can, both w/open rear tube.

It really already has a sort of catch-can to begin with, built into the filter housing. Funny, because it is called "Primary Oil Separator". I have yet to find anything listed as a "Secondary Oil Separator". However, this only separates oil from the vapor from the lower crankcase vapors being routed to the pcv and then the removed oil is introduced back into the oil supply. Any vapors recycling in the upper half due to valve blow-by will be recycled into the turbo-inlet. Most catch-cans mostly catch more water than oil due to this.


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## TimS78 (Nov 8, 2012)

Isn't it the latest revision that has the check valve in the PCV? I've replaced those parts in the last couple of months, and the latest rev PCV (06F129101R) has the check valve while the breather pipe I was sent just last week (06F103213N) is completely hollow.


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## ROH ECHT (Dec 9, 2010)

TimS78 said:


> Isn't it the latest revision that has the check valve in the PCV? I've replaced those parts in the last couple of months, and the latest rev PCV (06F129101R) has the check valve while the breather pipe I was sent just last week (06F103213N) is completely hollow.


Yes, but it is the latest revision for these pcv's with the valves inside it rather than one in the rear tube. PCV 06F129101R is the latest revision for these:
06F129101L
06F129101C
06F129101N
06F129101F
06F129101K

McVee is saying his has the valve in the rear tube.
PCV w/ PN;06F129101'P' is for those cars with the valve placed in the rear tube. VW obviously need to keep producing both pcv's because not all cars out there have the valved rear tube or went through the open campaign to convert it.

It was confusing for so many when the did the switch initially. What is important for people is to understand if their pcv has that pressure release valve in the pcv...then the rear tube needs to be valveless. And if the pcv is valveless there, then the rear tube needs to be valved. Still a mess I know :facepalm:


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## McVee (Nov 20, 2009)

Oh great stuff. Ok so I purchased this PCV https://runautoparts.com.au/audi-vw-pcv-valve
Checked it and it has the check valve 
So I presume this means I can remove the rear check valve.
And actually I don't even know if the rear breather even has a check valve. Car's a Golf R MY2013 but Australian.

I'll see how it sounds first with just this installed as the rear breather looks hard to access and has annoying single use hose clamps :banghead:
I probably would be uncomfortable removing it without having a replacement handy also. It's a pity the extra bit of rubber hose doesn't come with the metal breather tube. That seems quite expensive to buy separate!


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## ROH ECHT (Dec 9, 2010)

McVee said:


> Oh great stuff. Ok so I purchased this PCV https://runautoparts.com.au/audi-vw-pcv-valve
> Checked it and it has the check valve
> So I presume this means I can remove the rear check valve.
> And actually I don't even know if the rear breather even has a check valve. Car's a Golf R MY2013 but Australian.
> ...


Right, you can use a rear breather tube without the valve. When you remove the PITA clamp, you can replace it with a reusable clamp. Getting to the two small bolts for the tube is sort of tough. I use a thin strip of duct tape and tape a 1/4" bit into a 1/4" wrench. You can try anything you can think of. The short rubber hose should be OK. Also, the gasket between the tube and turbo inlet is a crush gasket and meant for one time usage. Up to you if to use it again.


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## McVee (Nov 20, 2009)

So that was a bit of a failure, for some reason the hole centers on the Vaico PCV valve were too wide and it was difficult to get it to seal properly.
I ended putting the "original" back on. I did get it to seal the vacuum, and there was no change to the single putt sound when dropping to idle.
I didn't drive though to test for the gurgling between 2-3000rpm though.

I wonder if the original housing itself was aftermarket (i.e. what the PCV valve attaches to).
The part number for the "original" PCV rakes me to russian and polish websites only, very odd: "39 111 32 102"

Link to picture: https://i.imgur.com/XNAIFRQ.jpg

I might just drill the holes out larger as you can see they are smaller than the previous one.
That should correct for some hole center discrepancy.


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## ROH ECHT (Dec 9, 2010)

OEM vs aftermarket is in some cases the same. I say that because VW, and most makers, do not make their bits. They contract out to have them made, as you probably know. The difference is the car's maker usually has stricter quality standards and toss out those bits that fail. This causes the contracted part maker to provide the best to the car makers.

Weird that the VAICO, from them, is $20 more than the oem from ECS: https://www.ecstuning.com/b-genuine...7VbRAbZF-2m-oGlSPS0BJPwPOx1AaEqwaAuX7EALw_wcB

I suppose if you showed the place of purchase that the dimension between those holes differs and it is near impossible to mount and impossible for it to seal...they would take it back on return. Enlarging the holes should work if you decide that's the way for you to go at this point. I still use oem parts, but when they arrive, I do look at the maker which is always printed on the VW box for the part.

You did replace the rear tube, yes?


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## McVee (Nov 20, 2009)

ROH ECHT said:


> You did replace the rear tube, yes?


I ended up drilling the holes out and it sealed well. The tapping when engine speed dropped to idle dissapeared on its own after a little bit.

The sound it makes at around 2000rpm is still there, but it's kind of improved and I like it actually.

So no I haven't replaced the rear breather.
Though I do have some power loss/engine retarding issues, and so am in the process of replacing most old components so might as well replace it anyway


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## akdarsh (Jul 13, 2020)

ROH ECHT said:


> You should do the check valve delete if running a catch can or block off plate...removing the check valve messes with the oem pcv functioning properly if the pcv is the revision with the boost check valve removed...because it was moved to the rear tube.


What happens if you run the rear breather tube with check valve (P/N 06F103215B) with catch can setup? I'm not hearing any puttering or anything, but I've started leaking a lot more oil lately, mainly from the cam cover/cradle. Do you think the check valve isn't opening, causing all the blowby to escape through cam cradle?


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## Thy_Harrowing (Dec 7, 2014)

akdarsh said:


> What happens if you run the rear breather tube with check valve (P/N 06F103215B) with catch can setup? I'm not hearing any puttering or anything, but I've started leaking a lot more oil lately, mainly from the cam cover/cradle. Do you think the check valve isn't opening, causing all the blowby to escape through cam cradle?


Sounds like excessive crankcase pressure if it is indeed just since installing the catch can. I'd delete the check valve, but keep in mind that the leak may continue if the seal is already compromised. You may or may not save yourself at this point, especially if it is coming from the cam cradle itself as you have reported (opposed to the valve cover gasket). The cam cradle is sealed with a bead of sealant which hardens over time so, once it is compromised, that's probably it; whereas the valve cover gasket should only leak with excessive pressure but otherwise seal fine after the excessive pressure is dealt with (provided the gasket was not damaged in the process which is unlikely unless it's very old and hard).

I'd also recommend you buy a spare rear breather with check valve to have ready in case you decide to ditch the catch can setup in Winter or just in general since they are overrated. I no longer run a catch can and generally don't recommend them for most people any more. I've come to that conclusion over the many years of more thorough education on these cars (and few different setups I've had personally) since I originally posted this thread years ago. I can elaborate on that conclusion more if you like.


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## akdarsh (Jul 13, 2020)

Thy_Harrowing said:


> Sounds like excessive crankcase pressure if it is indeed just since installing the catch can. I'd delete the check valve, but keep in mind that the leak may continue if the seal is already compromised. You may or may not save yourself at this point, especially if it is coming from the cam cradle itself as you have reported (opposed to the valve cover gasket). The cam cradle is sealed with a bead of sealant which hardens over time so, once it is compromised, that's probably it; whereas the valve cover gasket should only leak with excessive pressure but otherwise seal fine after the excessive pressure is dealt with (provided the gasket was not damaged in the process which is unlikely unless it's very old and hard).
> 
> I'd also recommend you buy a spare rear breather with check valve to have ready in case you decide to ditch the catch can setup in Winter or just in general since they are overrated. I no longer run a catch can and generally don't recommend them for most people any more. I've come to that conclusion over the many years of more thorough education on these cars (and few different setups I've had personally) since I originally posted this thread years ago. I can elaborate on that conclusion more if you like.


Yeah I was also originally debating whether a CC was worth it...but let me tell you why I think it's a good application for me.
I've been dealing with this leaking cam cover since I bought the car a couple months ago. Previous owner replaced camshafts, cam follower, HPFP 9 months ago, so they had to have resealed it then with the green sealant. I'm not looking to spend another $1100 9 months later:banghead:
I'm running an APR tune with more than factory boost, and I narrowed it down to bad PCV valves. I replaced the OEM one with Beck/Arnley PCV valve, and the cam cover joint was completely dry. 3 days later, the PCV valve developed a vacuum leak (hissing noise), but still kept the cam cover dry. I had a p0171 code so I replaced Beck/Arnley PCV with another OEM one. I don't believe it was ever as dry as it was with the B/A valve. Basically, I went through 2-3 PCV valves in a month. Decided it was time to try a CC setup.

Installed a 034 Motorsport PCV adapter plate and cut lines with nylon braided stainless steel core CPE fuel hose off Amazon with ~10AN fittings. The adapter plate didn't sit flush with valve cover, so oil leaked onto the cam cover joint once again....turns out the plastic valve cover was warped. I put a new valve cover on last weekend, and it's leaking more than it did before! My belief is either 1) there isn't enough green sealant to hold the pressurized oil in or 2) the rear breather should be running without check valve.

Elaborating on 2), I feel like a new VC will have more defined passageways that don't allow blowby to vent, causing it to leak from cam cover. Under what condition does the check valve in the rear breather tube open?


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## Thy_Harrowing (Dec 7, 2014)

akdarsh said:


> Yeah I was also originally debating whether a CC was worth it...but let me tell you why I think it's a good application for me.
> I've been dealing with this leaking cam cover since I bought the car a couple months ago. Previous owner replaced camshafts, cam follower, HPFP 9 months ago, so they had to have resealed it then with the green sealant. I'm not looking to spend another $1100 9 months later:banghead:
> I'm running an APR tune with more than factory boost, and I narrowed it down to bad PCV valves. I replaced the OEM one with Beck/Arnley PCV valve, and the cam cover joint was completely dry. 3 days later, the PCV valve developed a vacuum leak (hissing noise), but still kept the cam cover dry. I had a p0171 code so I replaced Beck/Arnley PCV with another OEM one. I don't believe it was ever as dry as it was with the B/A valve. Basically, I went through 2-3 PCV valves in a month. Decided it was time to try a CC setup.
> 
> ...



What version front PCVs were you trying? If you had an older version then it wasn't designed to be used with a rear PCV breather that has a check valve. ROH ECHT explained the different behavior of different versions of the PCV system earlier in this thread so check that out. I would only recommend the latest revision of front PCV. This one has been proven to be quite reliable on stock cars and also pretty reliable with decent longevity on tuned cars. As for your question regarding the check valve behavior, I could explain in words but I think it'll be more helpful if I send you a detailed diagram of the PCV system (and many other systems on the car) because you know what they say about pictures vs. words. Just have to dig up the link, give me a bit...


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## akdarsh (Jul 13, 2020)

Thy_Harrowing said:


> What version front PCVs were you trying? If you had an older version then it wasn't designed to be used with a rear PCV breather that has a check valve. ROH ECHT explained the different behavior of different versions of the PCV system earlier in this thread so check that out. I would only recommend the latest revision of front PCV. This one has been proven to be quite reliable on stock cars and also pretty reliable with decent longevity on tuned cars. As for your question regarding the check valve behavior, I could explain in words but I think it'll be more helpful if I send you a detailed diagram of the PCV system (and many other systems on the car) because you know what they say about pictures vs. words. Just have to dig up the link, give me a bit...


I appreciate all the help!

I've been running the latest revision front PCVs without the check valve (P/N 06F129101P). I did take a look at ROH ECHT's explanations, I've always been pairing non-check valve PCV with yes-check valve rear breather tube. I just forgot to swap out the rear breather with check valve when I installed my catch can. Now that I think about it, it's making more and more sense that it could be a legitimate cause for my leakage.


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## Thy_Harrowing (Dec 7, 2014)

akdarsh said:


> I appreciate all the help!
> 
> I've been running the latest revision front PCVs without the check valve (P/N 06F129101P). I did take a look at ROH ECHT's explanations, I've always been pairing non-check valve PCV with yes-check valve rear breather tube. I just forgot to swap out the rear breather with check valve when I installed my catch can. Now that I think about it, it's making more and more sense that it could be a legitimate cause for my leakage.


Yes the check valve in the rear sounds to be causing excessive crankcase pressure now with your catch can. I think you should delete it. But as I mentioned previously, the nature of your leak around areas like the cam girdle may not improve even after you've done so if the seal is already compromised. The cam chain cover may or may not continue leaking for the same reason as it does not get the green sealant the cam girdle does but it does get a very thin metal gasket.

Here is the link I mentioned. Navigate to the diagram for the PCV system and hopefully it will be helpful in understanding in what conditions the rear PCV check valve opens, etc.

https://drive.google.com/file/d/0Bzeazv76x9MXUjF1a1FSUFJkdFE/view?usp=sharing


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## ROH ECHT (Dec 9, 2010)

The rear breather tube's check valve opens when crankcase pressure is present...it should seal when in vacuum. If it isn't opening...this would cause blowouts at seals, and why it is better to have an open rear breather tube when a catch-can or pcv delete is installed. 

Catch-cans to me are unnecessary...because there are two oil separators already built-in. One within the oil filter housing assembly and the second is within the valve/rocker cover. Catch-cans mostly collect more moisture than they do oil.


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## Thy_Harrowing (Dec 7, 2014)

ROH ECHT said:


> The rear breather tube's check valve opens when crankcase pressure is present...it should seal when in vacuum. If it isn't opening...this would cause blowouts at seals, and why it is better to have an open rear breather tube when a catch-can or pcv delete is installed.
> 
> Catch-cans to me are unnecessary...because there are two oil separators already built-in. One within the oil filter housing assembly and the second is within the valve/rocker cover. Catch-cans mostly collect more moisture than they do oil.


Well said as always 👍


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## akdarsh (Jul 13, 2020)

ROH ECHT said:


> The rear breather tube's check valve opens when crankcase pressure is present...it should seal when in vacuum. If it isn't opening...this would cause blowouts at seals, and why it is better to have an open rear breather tube when a catch-can or pcv delete is installed.
> 
> Catch-cans to me are unnecessary...because there are two oil separators already built-in. One within the oil filter housing assembly and the second is within the valve/rocker cover. Catch-cans mostly collect more moisture than they do oil.


I also didn't think I'd need a catch can...until I went through 3 PCVs in a month

Now that I think about it, though, there really is no solid proof that my PCVs were bad. I've always been going off the amount of oil seepage at my cam cover. When I installed a Beck/Arnley PCV, any and all leaking stopped COMPLETELY for 3 days. Then it started again, and I heard hissing from the PCV with a p0171 code, so I knew for sure that it broke under boost and developed a vacuum leak. But when I install brand new Genuine VW PCV valves, I don't see too much reduction in oil seepage. It's just a spring-loaded diaphragm, right? 
Not sure why B/A vs Genuine VW PCV valves have such a drastic impact on my cam cover leaking. 

As for the non-check valve rear breather tube, I have a spare one (P/N 06F103215B). I'll try breaking off the check valve with a Phillips screwdriver and hammer and install it this weekend. Will keep you all in the loop.

Once again, thanks for all the feedback!


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## Thy_Harrowing (Dec 7, 2014)

I doubt the B/A was actually responsible for the difference in seepage compared the others up until the point they stopped working properly. More likely your seepage “solution” during those 3 days was circumstantial due to any number of factors such as how you were driving during that limited period of time compared to in general. 

The B/A and any other aftermarket PCV will be designed to function the same way to OEM spec, albeit cheaper and even less reliable as you found out when it failed in 3 days. While functioning correctly crankcase pressure and related behaviors should be the same between the aftermarket and OEM part so, again, I think your observation is a false positive and didn’t have to do with the B/A part vs OEM. 

If you have no evidence that PCVs are failing often besides the one immediate failure of an aftermarket copy (not unsurprising) then I’d still suggest going back to a latest revision OEM PCV and calling it a day. But if you want to experiment with the catch can and rear check valve delete first I don’t blame you.


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## akdarsh (Jul 13, 2020)

Thy_Harrowing said:


> Sounds like excessive crankcase pressure if it is indeed just since installing the catch can. I'd delete the check valve, but keep in mind that the leak may continue if the seal is already compromised. You may or may not save yourself at this point, especially if it is coming from the cam cradle itself as you have reported (opposed to the valve cover gasket). The cam cradle is sealed with a bead of sealant which hardens over time so, once it is compromised, that's probably it; whereas the valve cover gasket should only leak with excessive pressure but otherwise seal fine after the excessive pressure is dealt with (provided the gasket was not damaged in the process which is unlikely unless it's very old and hard).
> 
> I'd also recommend you buy a spare rear breather with check valve to have ready in case you decide to ditch the catch can setup in Winter or just in general since they are overrated. I no longer run a catch can and generally don't recommend them for most people any more. I've come to that conclusion over the many years of more thorough education on these cars (and few different setups I've had personally) since I originally posted this thread years ago. I can elaborate on that conclusion more if you like.



Put the modified rear breather in, leaking slowed down a decent amount, but like you mentioned there's not enough sealant to hold the oil back --> still a little seepage. I think I'm going to go in and reseal it myself. Anyone have a DIY for this? Do I need to use a cam-lock tool? Or will the timing chain tension keep the cams from shifting? I feel like even if I use a cam-lock tool, it'll only help with the exhaust cam, not the intake cam. Planning to just mark the timing gears with paint as a precaution.
To get the cam carrier out, I need to remove: valve cover, HPFP, and cam follower, right? Anything else I'm leaving out?


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## Thy_Harrowing (Dec 7, 2014)

akdarsh said:


> Put the modified rear breather in, leaking slowed down a decent amount, but like you mentioned there's not enough sealant to hold the oil back --> still a little seepage. I think I'm going to go in and reseal it myself. Anyone have a DIY for this? Do I need to use a cam-lock tool? Or will the timing chain tension keep the cams from shifting? I feel like even if I use a cam-lock tool, it'll only help with the exhaust cam, not the intake cam. Planning to just mark the timing gears with paint as a precaution.
> To get the cam carrier out, I need to remove: valve cover, HPFP, and cam follower, right? Anything else I'm leaving out?


The cams are ON TOP of the cam girdle... in order for the girdle to come out, the mating surface to be well cleaned and then resealed with ANAEROBIC sealant, you need to remove the cams entirely. So the valve cover, HPFP, cam follower, cam chain cover, cam chain tensioner, chain itself, and cams themselves all must come out. Yes make marks because you'll obviously need to retime everything afterward.

Again, the sealant you use for the cam girdle must be anaerobic sealant or it will fail. That's what that special green VW sealant is. There are other cheaper types, I think Permatex and/or Loctite have one, but I don't chance it and I use the VW green stuff. Stupid expensive, but I wouldn't take ANY chances when it comes to a job like that. I'd be damned if I had to do it again because I cheaped out on sealant lol. The cam chain cover is technically not supposed to get any sealant but you must order a new gasket. The gasket has "sealant" on it already but I was always a little iffy about it so in the past I have use a VERY thin bead of Elring Dirko high temp silicone sealant for the cam chain cover. The valve cover gasket must be replaced as well and it does NOT get sealant. Unlike the cam chain cover thin metal gasket, the valve cover gasket is basically just like an o-ring (same material) so it only gets a light coating of fresh oil to promote a good seal as you tighten the valve cover back down. All mating surfaces for all of the aforementioned gaskets should be cleaned thoroughly before resealing.


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## akdarsh (Jul 13, 2020)

Thy_Harrowing said:


> The cams are ON TOP of the cam girdle... in order for the girdle to come out, the mating surface to be well cleaned and then resealed with ANAEROBIC sealant, you need to remove the cams entirely. So the valve cover, HPFP, cam follower, cam chain cover, cam chain tensioner, chain itself, and cams themselves all must come out. Yes make marks because you'll obviously need to retime everything afterward.
> 
> Again, the sealant you use for the cam girdle must be anaerobic sealant or it will fail. That's what that special green VW sealant is. There are other cheaper types, I think Permatex and/or Loctite have one, but I don't chance it and I use the VW green stuff. Stupid expensive, but I wouldn't take ANY chances when it comes to a job like that. I'd be damned if I had to do it again because I cheaped out on sealant lol. The cam chain cover is technically not supposed to get any sealant but you must order a new gasket. The gasket has "sealant" on it already but I was always a little iffy about it so in the past I have use a VERY thin bead of Elring Dirko high temp silicone sealant for the cam chain cover. The valve cover gasket must be replaced as well and it does NOT get sealant. Unlike the cam chain cover thin metal gasket, the valve cover gasket is basically just like an o-ring (same material) so it only gets a light coating of fresh oil to promote a good seal as you tighten the valve cover back down. All mating surfaces for all of the aforementioned gaskets should be cleaned thoroughly before resealing.


Wait...this is where I get completely lost. I don't think we're talking about the same thing...?
I'm trying to reseal the joint immediately below where the valve cover gasket is. See the pic below: Red arrow is VC gasket, yellow arrow is cam carrier joint I'm looking to reseal. This pic is pretty old, you can't even see the green sealant anymore now it's just oil.
https://drive.google.com/file/d/1dOGb-4_n2nuP5derew4PB62ljdSQQ1D5/view?usp=sharing

The cam carrier/girdle/whatever it's called has 2 Torx looking bolts per cam and then a bunch of other bolts around the outsides (blue arrows).
https://drive.google.com/file/d/11fKt62YPT22_-ugEoMj2ew1BHM_C34VI/view?usp=sharing
I'm fairly certain this carrier locks down the camshaft. Removing it may cause the exhaust camshaft to pop out a little bit, but the tension in the chain should lock it pretty tight. 

Found this video for TSI, but the procedure should be pretty similar: Again, I don't think the camshafts sit on top of the cam carrier. From what I can tell, (and what makes sense to me) is that they stay in the engine during all this. Around 11:50 is when you get a good view of the engine bay.
https://www.youtube.com/watch?v=2HpQjPsepR0

Adding witness marks/paint to the timing gears is just a precaution, IN CASE a camshaft pops out more than anticipated. (should be 1-2 degrees max). After resealing it and installing, I believe the notches in the cam carrier will/should line up with the notches in the camshaft, and force them to rotate back to their original position.

Of course, I've never done this before and this is what I thought the process looks like. Some other forums describe similar processes. Seems like you've done it though so I'll take any input I can get.


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## Thy_Harrowing (Dec 7, 2014)

akdarsh said:


> Wait...this is where I get completely lost. I don't think we're talking about the same thing...?
> I'm trying to reseal the joint immediately below where the valve cover gasket is. See the pic below: Red arrow is VC gasket, yellow arrow is cam carrier joint I'm looking to reseal. This pic is pretty old, you can't even see the green sealant anymore now it's just oil.
> https://drive.google.com/file/d/1dOGb-4_n2nuP5derew4PB62ljdSQQ1D5/view?usp=sharing
> 
> ...


Nope, you're correct! I don't even remember exactly what was going through my mind last night when I posted that. Don't know if I was thinking of a different job on a different engine platform or if I was just getting steps and such mixed up because I have had the cams out as well and maybe I thought I remembered removing the cam girdle/carrier/cage/whatever after instead of before. Not really sure, but that was my mistake, sorry if I gave you a heart attack. I think your plan of action is sound


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## akdarsh (Jul 13, 2020)

Thy_Harrowing said:


> Nope, you're correct! I don't even remember exactly what was going through my mind last night when I posted that. Don't know if I was thinking of a different job on a different engine platform or if I was just getting steps and such mixed up because I have had the cams out as well and maybe I thought I remembered removing the cam girdle/carrier/cage/whatever after instead of before. Not really sure, but that was my mistake, sorry if I gave you a heart attack. I think your plan of action is sound


Oh thank God, you really had me worried there! Thanks for the clarification.
Quick question about "worst case" scenario: In case the cam position shifts more than 2-3 degrees, and I need to rotate it back to the original witness mark, how can I rotate the camshaft? I'm assuming not by hand, but is there some sort of protruding "inverse head" on the cam gear I can throw a spanner on? Or do I need a VW tool that aligns with some sort of key in the cam gear?

https://drive.google.com/file/d/1S32PDXmREbUy0-qaixYLlfJm5w_p0NTf/view?usp=sharing
It looks like the exhaust cam gear has a head that can be used to turn it...but I don't see a cam gear at all for the intake camshaft. Is it on the other side of the engine? Where is the timing for it?


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## TimS78 (Nov 8, 2012)

akdarsh said:


> Oh thank God, you really had me worried there! Thanks for the clarification.
> Quick question about "worst case" scenario: In case the cam position shifts more than 2-3 degrees, and I need to rotate it back to the original witness mark, how can I rotate the camshaft? I'm assuming not by hand, but is there some sort of protruding "inverse head" on the cam gear I can throw a spanner on? Or do I need a VW tool that aligns with some sort of key in the cam gear?
> 
> https://drive.google.com/file/d/1S32PDXmREbUy0-qaixYLlfJm5w_p0NTf/view?usp=sharing
> It looks like the exhaust cam gear has a head that can be used to turn it...but I don't see a cam gear at all for the intake camshaft. Is it on the other side of the engine? Where is the timing for it?


The intake cam is driven off the exhaust cam by a chain at the opposite end of the engine - to pull the cams, you'll need to remove the HPFP/vacuum pump/N205 housing as well, and . Once that housing is off, you'll see the cam adjuster and timing chain. The slot cut into the end of the intake cam can be used to rotate it if it's out of time.


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## akdarsh (Jul 13, 2020)

TimS78 said:


> The intake cam is driven off the exhaust cam by a chain at the opposite end of the engine - to pull the cams, you'll need to remove the HPFP/vacuum pump/N205 housing as well, and . Once that housing is off, you'll see the cam adjuster and timing chain. The slot cut into the end of the intake cam can be used to rotate it if it's out of time.


Ok thanks for the information. I'm still a bit confused...sorry for all the questions! Just want to make sure I don't completely destroy my engine 

So once the valve cover is off, what exactly needs to come out to remove JUST the cam carrier? Can I remove the bolts marked in blue below and expect the cam carrier to come out?
https://drive.google.com/file/d/1C-A4v-GZ2ZZxFwf3jmrfAbAMxsNhtl7q/view?usp=sharing

Or do I need to remove anything more on the left and right side of the engine? I'm pretty sure upper timing cover can stay on (aside from the 2 valve cover bolts). Let me know if HPFP/cam follower absolutely has to come off.
The cam carrrier at 4:43 matches the bolts I'd expect to remove I mentioned above. 
https://www.youtube.com/watch?v=Ob_zr9y1prE

Again, sorry to keep looping back to this...


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## TimS78 (Nov 8, 2012)

I've never removed the cams on this engine, but I don't see how you'll do the job without removing the HPFP/cam adjuster housing - it appears to be bolted to both the cam cradle and the lower cylinder head. There are 7 bolts holding it on; a set of long torx sockets for your ratchet will make the job much much easier. You're also going to want new seal rings for the N205 valve - I used this kit from amazon and it worked great: 

https://www.amazon.com/dp/B07G9NDWS...olid=2R3PAJYGQJS3T&psc=1&ref_=lv_ov_lig_dp_it

Also, depending on your mileage, it might be a good time to go ahead and replace the cam adjuster chain and tensioner while you're in there.


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