# 3.2 VR-6 (BUB) PCV Diaphragm Replacement Alternative



## SwissJetPilot

Unlike the Audi TT Mk2 1.8, 2.0 or 2.5 liter engines, the 3.2 VR-6 (BUB) Pollution Control Valve (PCV) diaphragm is located inside the Valve Cover "hump" directly behind the oil cap. Inside that hump, you'll find the Cyclone Oil Separator (COS) and inside the COS you'll find the PCV diaphragm (aka Vacuum Valve). Unfortunately, neither the COS or PCV diaphragm are available as individual replacement parts. Instead Audi will happily sell you the entire valve cover for around $425. If you have it replaced by Audi Service, expect to shell out somewhere around $800 for parts and labor. Keep in mind that's $800 to replace a $35 part!

This post will discuss the option of simply replacing the TT vent tube with a Touareg vent tube which has an external PCV diaphragm built in. It's a simple one-to-one swap with only a minor modification that anyone can do themselves.






































At some point in time, that internal diaphragm will fail, and when it does the MIL light will come on and the OBD will register one of these faults; 18711, P2279 or 008825 indicating a leak in Air Intake System. In addition to the MIL light, you'll hear a whistle coming from the back of the valve cover, from a tiny little vent hole above where the vent tube connects from the valve cover to the intake manifold.

You can see and hear it demonstrated in this YouTube video for a VW R32 MkV Golf -

*Vacuum Leak VW R32*
www.youtube.com/watch?v=Wl7guwee8u0&t










Fortunately, you can buy a non-OEM diaphragm as an individual part for around $30 (USD) from a third party such as *RKX Tech*. However you still have to remove the intake manifold and valve cover, and of course replace all the respective gaskets when putting it all back together. If you want to see what's involved in replacing the PCV diaphragm watch this YouTube video -

*How to: VW & Audi 3.6, 3.2 PCV valve membrane replacement*
www.youtube.com/watch?v=PmI-oH8wMRc&t=1s

*V6-3.2ltr PCV/CCV Failure & Replacement*
https://www.ttforum.co.uk/forum/viewtop ... &p=9043581


















After a bit of research on other PCV designs for other VAG engines, I discovered that the VW Toureg uses a similar breather tube but with the PCV diaphragm built in which is designed to sit externally to the valve cover. So it's much easier to get to when the diaphragm fails. Both the TT Breather Tube and Toureg PCV tube have the N79 Heating Element connector and the overall geometry is identical so it a simple one-to-one swap.

FYI - if you get the following fault code - *18711/P2279/008825 - Leak in Air Intake System* - this can be related to a faulty Positive Crankcase Ventilation (PCV) System or the N79 Heating Element.

*TT vent tube on top, Touareg vent tube below -*










*OEM TT vent tube on the left replaced with a Touareg PCV vent tube on the right -*










_(Image credit A3-Quattro.de)_


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## IPG3.6

It's a good idea but where you gunna put it? I have a feeling it'll messy up the engine bay too much.


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## SwissJetPilot

@ *IPG3.6* - I've ordered a Touareg PCV hose (shown below on an actual Touareg) and will take a look at whether or not it will fit. Swapping Touareg PCV for the TT breather tube would be the easy fix it if will work. They look exactly the same size and length, so it should be a straight forward one-to-one swap.

According to the *7zap parts *website Part Number *022.103.765A* and *022.103.245B* are used on a number of 6-cylinder engines; AZZ, BMV, BAA, BMX, BKJ, and BRJ for both the Touareg and Phaeton.


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## Oldboater

I know I'm new around here, but my opinion for what it's worth is that personally I would fit the $30 part. What you save on the price (maybe $15 on the difference between the external PCV valve and the diaphragm kit prices ) plus the fact you will be able to take a look under the covers when doing fitting the diaphragm...and keeping a tidy engine bay will help preserve the resale value should you ever wish to part company with your 3.2.......

Just an opinion and it may be wrong! 8)


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## SwissJetPilot

@ *Oldboater* - Yes, you're right. But let's say the internal PCV diaphragm fails when I'm on holiday and miles from home. I can't just pop into the local auto parts store, buy a replacement PCV diaphragm and swap it out in the hotel parking lot. This is why I hope the Touareg PCV swap will work.

Here's a YouTube video and link to what it takes to get the valve cover off. Only Audi would take a simple $5 part and design into a location that costs me $250 in labor just to get to it! 






*VR6 3.2 (BUB) Engine Valve Cover Removal*
https://forums.vwvortex.com/showthread. ... ms-Install


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## SwissJetPilot

Latest update on this potential workaround. I removed the TT Vent Tube and replaced it with a Touareg PCV to verify fit and function.

The three stand-offs on the Intake Manifold are pretty strong and with some kind words of encouragement from *IPG3.6*, I managed to get the TT Vent Tube off. The trick is to use a small nylon pry bar (a screwdriver will work, but you really don't want to break the Manifold stand-offs) to release each clip. Then I inserted a stiff piece of plastic shim (plastic credit card stock or old hotel key card) in between the stand-off and the clip so the clips can't snap back. I shimmed each one and then pulled it straight up and out.

*NOTE* - You'll notice the clips on the TT and Tourareg are slightly different as the TT fits inside the stand-offs, while the Touareg fit over the stand-offs. Also important to note, one of the stand-offs is keyed with two small bumps to ensure the PCV can only be fitted on way. The Touraeg clip is also keyed, so just be aware of this especially if you are using a non-OEM PCV. If it doesn't have the notches, it may break the clip.

During my installation, the fit at both ends was perfect and the N79 heater connector is identical. After letting the engine run for about 5-minutes or so, no lights came on and the engine sounded exactly as before and I couldn't hear any vacuum leaks. I then removed the Touareg PCV and swapped it back for the TT Vent Tube. As before, there was no noticeable difference. So I think that at least proves the two designs and their respective fittings are 100% interchangeable and vacuum tight.

The only other thing that would have to be done when the internal diaphragm fails, is to block the small 3mm vent hole just above where the Vent Tube connects to the hump at the back of the Valve Cover. This will be where the vacuum leak will occur when the internal diaphragm fails. A small self tapping or fine pitch stainless steel *M4* screw with Loctite should be an ideal permanent solution, or dab of Permatex® High-Temp Red RTV Silicone Gasket Maker.

*NOTE* - Be aware that screwing a steel screw into an aluminum valve cover could lead to galvanic corrosion between the dissimilar materials. An aluminum screw would be the best solution, however if you go with a steel screw use 316 Stainless Steel rather than plain steel or galvanized. The use of Loctite should help minimize any metal to metal contact. If you don't have a tap set handy, you can use a steel *M4* screw with the same thread pitch as your aluminum screw to cut into the hole so the aluminum screw doesn't gall when installed.









*NOTE* - You should only block the valve cover vent hole WHEN THE INTERNAL DIAPHRAGM FAILS or it may adversely affect how the internal PCV diaphragm functions.


















*Pay attention to the stand-off closest to the vent hole in the valve cover as it is keyed with two protrusions. This is to ensured the Touareg PCV is installed in the correct orientation. If you install a non-OEM PCV vent tube, you may need to cut notches in the tab to it will fit properly or you may end up breaking the clip when you try to install it. *


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## Wolvez

VAG engineers are really doing a great job on making something simple very complicated.


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## SwissJetPilot

And bloody expensive!  Another advantage of using the Touraeg PCV is the diaphragm can be replaced quite easily -


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## IPG3.6

Nice work and love your unconventional thinking to expand the solutions to our cars. As parts become less and less available ideas like this are going to be life savers!


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## Magnus32

Hi guys

I know I am resurrecting an old thread here but the search function didn't come up with anything!

Do we know if anyone has attempted this fix alternative, and if so, was it successful?

I have just ordered the parts to attempt it myself, as I have just had the dreaded PCV failure, and no way do I want the 7 hour labour bill to get that head cover off


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## SwissJetPilot

@ *Magnus32* - I've been running with the Toureg PVC tube installed in my TT for a while now without any problems. However, the PCV diaphragm inside the valve cover hasn't yet failed. But at least this proves the Toureg PCV doesn't affect the airflow or trigger a MIL light on the dash.

Since yours has failed, the only way to know for sure that this will concept will work is to install the Toureg PCV tube, start the engine and block the hole in the valve cover with your finger (while the engine is still cold so you don't burn yourself) and see if that stops the leak and eliminates the fault.

If that does work, you can try blocking the hole with a dab of High-Temp Red RTV Silicone (rather than installing a screw) drive it for a while and see how that holds up. Obviously a self-tapping screw would be a more permanent solution.

Word of Caution - removing the OEM PCV clips from the intake manifold is a PITA! Take your time, and try to shim each one with a plastic pry bar or shims stock rather than using a metal tool (e.g. a screwdriver). Anytime I have to work with plastic on plastic, I prefer to use plastic tools.

The manifold clips are quite rigid so you want to deflect the PCV clips inwards so they are out of the slots in order to get them free. I shimmed and released each one at a time, and as it came free, I lifted it up and shoved the shim in so the clip couldn't re-engage. Once you get them all free, it comes away easily enough.

If you look carefully, you'll notice the Toureg PCV clips are a slightly different design as they are intended to fit outside and over, rather than inside, the manifold clips.

Looking forward to how this works out!


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## Magnus32

Thank you @SwissJetPilot

All bits ordered, including some m2 screws! I will pop a bit of silicone over it for a test run and report back.
At the moment, with the diaghraphm faulty, if I put my finger over that hole, it runs like a bag of spanners! Sounds awful! 
So hopefully that won't be the case when I get the Toureg pipe on. Fingers crossed  
If this works I will be absolutely delighted. I really do not fancy stripping the front of the car down!


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## SwissJetPilot

@ *Magnus32* - If you would be so kind, please post some pictures of your efforts and let us know what issues you run into.

Just out of interest, here's an x-ray image of what's inside the OEM TT vent tube. The dark item is the N79 heater element. 








_(Image credit A3-Quattro.de)_


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## Magnus32

Worst case, I end up putting the Toureg breather on ebay and getting a few quid back that I paid for it and getting in to my friends workshop one weekend and rolling my sleeves up for a big old job of taking off the inlet manifold.

Audi specialist just got back to me, quoted £850 for them to do it. No thanks!

I will be sure to post pictures a long the way, and get my report back on here. If all goes to plan with deliveries, I should be attempting this on Wednesday. So I'll be back to let you know how I got on. I'll let it run, then take it up to the workshop and have the codes deleted, and pray they don't come back.

If this works, you are a genius, and a saviour!

I'm sure I read thread somewhere that V6RUL had done something similar, but I cannot for the life of me find it. Doesn't look like he is active anymore.


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## SwissJetPilot

It you need any reference material, the workshop manuals are listed in the Knowledge Base -

*FAQ - Audi TT (8J) Workshop Manuals & Self Study Programs*
https://www.ttforum.co.uk/forum/viewtop ... &t=1833829

*UPDATE* - If you look closely at the end of the tube that fits against the valve cover, you'll see NORMA NW 19. Evidently Norma Group is the company that owns the patent on the quick connector. A slightly larger version of this is used on the Secondary Air Pump.

I was looking for any other markings that might give away the OEM manufacturer, but all I could find was SP5 348 MBO which is similar to what's on the back of the Toureg PCV. A bit more digging and it looks like *Vierol AG* is the OEM manufacturer.

https://www.vierol-shop.de/en/listing/1 ... -50/page-2
Valve, engine block breather
V10-2795

The marking >PA66 GF35< simply refers to the type and composition the of plastic; *P*olyamide *66*, 35% *G*lass *F*ibre reinforced.


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## MT-V6

Posting just to subscribe


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## Magnus32

A little heads up, just got a message off the seller on ebay I have bought the Toureg hose from to say it is going to be next Wednsday for delivery now...
So looks like we will have to wait a little longer. Annoying, I hate driving my car with the EML on, although it runs fine on the move, the lumpy idle in stand still traffic drives me nuts.
Will keep journeys to a minimum for now and borrow the misses car where I can. Stay tuned!


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## SwissJetPilot




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## scot360

Hello Magnus32 and SwissJetPilot.

I also have the air getting sucked into the rocker cover through that small hole.
It took a while to find :roll:

So I have the split diaphragm inside the rocker cover.

I am very eager to do the toureg modification. I am very happy to modify my engine bay as even a potenial buyer would understand if you actaully told them, but nobody is going to notice.
I do my own mechanic work, but it looks a bit job.

I did notice the photo of the part shown and the part fitted looked different? 
The part fitted had a flat disc on top but the photo had a circular value type shape sticking up.
Magnus32 please let me know how its gone , im dying to get the part ordered.

EDIT ,I understand the part number now. Its the underneath that has the valve sticking up and the top is flat.


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## Magnus32

Will update as soon as possible. Still awaiting delivery of the part. I am impatient haha!
I'm not sure it is going to work to be honest, as the diaphragm/valve will be further up the chain, after the hole, and I think blocking the hole might not be a great idea, as I am sure it is there as a pressure releif sort of thing. When I put my finger over the hole, my car runs horribly and wants to cut out. I don't see how it will change much with the swap... BUT.... I am willing to try it out for the low cost and low effort that it is. So fingers crossed! Let's have a look what happens


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## SwissJetPilot

The little hole in the valve cover performs the same purpose as the one located on the top of the Toureg PCV as described in SSP 260 -

"_The diaphragm valve ensures a uniform pressure level and good ventilation of the crankcase. It is split into two chambers by a diaphragm. One chamber is connected to the outside air and the other to the intake manifold."_

This is why you can feel air coming out of the outside air inlet when the diaphragm fails as air can now pass through the diaphragm resulting in a leak in the system.

As far as I can tell, both the internal valve cover PCV and the external (Toureg) PCV components are all in the same orientation so the functionality should be identical.

But you're right, this concept simply moves everything upstream from the internal valve cover PCV to the top of the intake manifold using the Toureg PCV. However the location shouldn't make any difference as long as the system remains closed and there are no air leaks. Which is why the valve cover outside air inlet hole needs to be sealed if the internal diaphragm has ruptured.

Or at least that's the theory!


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## Magnus32

Ohhhhh, I did not see that hole on the back of the puck of the Toureg valve!! Ok... now I am even more positive.
I cannot bloody wait for this thing to get here and put it to the test for you!


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## motornoter

We're all looking forward to the outcome too. This could be a great workaround for us 3.2 litre owners when faced with this annoying - and expensive - issue!!


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## scot360

I have priced up the VW 022103765A part number £119 inc vat.

Febi Bilstein part number 47564 their part number is around £45.
I am just trying to order one this morning.

I am quite sure it will work.

I would like the VW part but I know that Febi actaully make 1000`s of parts for many manufacturers and it could be the exact same part made by Febi that VW use.


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## SwissJetPilot

@ *scot360* - You might try Amazon in the UK -


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## Magnus32

Febi make a lot of OEM parts, so I am not alarmed really.

My local TPS (with discount as I used to work for them) came out at £110 for the VW original, and would of taken 3 days to come in to stock anyway, so to save £60 and wait another 3 days seems reasonable.


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## motornoter

For that price, few pounds under £20, it's well worth giving it a go! Again, another brilliant TTF workaround to save us money and time when things go wrong. Thanks guys!!


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## SwissJetPilot

The key factor in making this work is a really good seal of the vent hole on the valve cover. The *M4 x 5* with a dab of Loctite will do the trick!


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## Magnus32

I got the screws that you mentioned in the first post about this. I have them downstairs, and I think they may be a bit too small for the hole. But we will see! I will be blocking it with your RTV method first, just to make sure it all works fine before popping a screw in. In which case, I will probably put a small amount of the RTV around the top end of the screw before popping it in too. Brilliant idea with the foil!

Update: 
I have messaged and messaged the seller on ebay, as they tracking on the item still shows it as not in transit, which has me worried. He has ignored all of my messages for the last 5 days, and now upon checking his feedback, there are 8 negative alone with comments such as "came 4 weeks late." "never turned up" etc etc. SO.....
I have bit the bullet and had TPS order me a genuine one... yes its more expensive, but it will be here tomorrow morning and I can crack on with the job and have peace of mind then.

Fingers crossed it comes in to stock and isn't a backorder item... they said the factory was only showing one on the shelf... I have had bad news with that "one on the shelf" thing before...


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## SwissJetPilot

I contacted the *RKXTech* Representative in the US and asked why the diaphragm was even necessary as I know some VWs have PCV delete kits. These kits effectively eliminate the PCV and are common mods when installing Catch Cans -

_If the valve cover was hooked up directly to the intake manifold via a tube it would put the crankcase under enormous vacuum and cause all sorts of issues. The spring on the diaphragm regulates that vacuum on the crankcase and changes how much flow there is at high vacuum vs low vacuum times (wide open throttle vs idle).

The PCV system can be set up in different ways for example routing to the intake before the throttle body to reduce vacuum applied to the crankcase. The problem is the PCV system is basically a calculated air leak inside of the system. So any changes in the the PCV flow would need to be coupled with tuning in the ECM. If you can come up with something that does not alter the PCV flow rate then that would work without turning. - Ryan Jacobson, RKX Tech Customer Service_

That comment about "tuning in the ECM" would probably have to be done with a VCDS or OBDeleven if the engine can't automatically compensate for the change by itself. But hopefully moving the PCV location 10-inches from it's current location won't make any difference. Guess we'll find out as soon as your parts arrive!

@ *Magnus32* - Can you cancel your order and get one off Amazon instead??


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## Magnus32

I'm willing to bet that the flow will be the same, if its pressurised, moving it a matter of inches up the system can't make that much of a difference surely - lots of the turbo lot delete their pcv and have catch cans fitted with no mapping to compensate for it. Even so, i'd imagine the electronic plug on the unit is probably some sort of measure for what is coming through, so it can monitor and adjust the system as neccessary. Something like a 3.2 V6 will be outputting all sorts of random pressures at different operating condititions all the time, so I bet it will be able to fine trim and adapt on the go. FINGERS CROSSED!
I'll fit it, drive up to the garage and have the EML turned out. If it runs fine and doesn't come back on... that should be a good sign


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## Magnus32

Best Amazon can do is 3 weeks lead-time


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## SwissJetPilot

The connector is for the N79 Heating Element, so the PCV is not sensing anything. I looked it up and evidently the N79 is always on as it's function is to vaporize any condensed water in the blow-by gasses during very cold temperature operation, thus preventing ice-blocking the system.


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## Magnus32

Don't sew the seed of doubt in my mind now that I'm all excited and forked out £150


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## SwissJetPilot

Of course it will work! For that kind of money how could it not!


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## Magnus32

It is on!

Not bunged the hole yet, I cleaned the RTV off as it looked very messy and I think it will blow off the minute I get out driving anyway.

I plugged it with a bit of rubber whilst I tested it out... and...

NO MORE LUMPY IDLE.... NO MORE AIR SUCKING/BLOWING.....

This is a good sign! I am off to a hardware shop to get a screw that will fit the hole, as the M2's that I ordered are too small.

I took some photos and will upload them when I am done...

Once this is bunged, I will go up to the garage and have the EML turned off


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## SwissJetPilot

So far, so good! Promising results! 

I will be very interested in the screw size/thread pitch you use and how you install it. You'll want to put some blue Loctite on the threads to ensure a good seal.That's going to be a big part of making this project work properly.


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## Magnus32

That's a bloody good idea!!

Ok for now, I have an M3 self tapper in the hole, with a little RTV around the head to seal it. It does not look very pretty at this stage, but it will do for now, as it seals it. I will be ordering a flat pin head style m3 self tapperwith o-ring online and swapping it for that as soon as possible, as that will look unnoticable and clean.

So the good news...
Took it to the workshop, had the fault codes deleted, and none have come back, after 50 minutes of mixed style driving, hard B-road, motorway, and stop start traffic.
It feels so much better, no more hissing noise, no more lumpy idle, no more revving up and down when stationary, gear changes feel smoother as its not trying to rev its tits off between shifts!

Apart from the screw, it looks completely OEM and as if its meant to be like that.

I think you may have nailed it with this idea SwissJetPilot! Lets see how the next few days go.


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## SwissJetPilot

Excellent! As the saying goes, "You're rounding third base and heading home!"

Good to know an *M4* screw is the way to go. I updated the previous comments above. When the one you ordered shows up, can you please post a picture before and after installation and also let us know your source.

I was just thinking, you may want to put *Blue Loctite 242* on the threads before you install it. You'll be screwing a steel screw into an aluminum cover, so the Loctite is just a caution against any galvanic reaction between the two dissimilar metals. Plus it will help seal the threads a bit.

And how was it getting the TT vent pipe off and the Toureg PCV installed? Any drama?

When you said "go to the garage" did you mean a shop, or to your personal garage? If you're having someone reset your fault codes, it might be time to invest in a VCDS or OBDeleven. Super easy to use and really helps sort out any problems.

One other comment, I noticed you've got a bit of snow on the plenum. Just a word of caution that you make sure those plenum drains are clear so you don't get water in the cabin. The DIY is easy-peasy -

*How to: Plenum Removal for Drain Inspection & Cleaning*
https://www.ttforum.co.uk/forum/viewtop ... &p=9379191


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## Magnus32

That is super helpful, thank you! I will attempt this job as soon as the weather dries out. One of my wiper arms has a slight bit of rust on it, so would be nice to swap it at the same time.

Luckily, many years ago, I worked at a garage as an apprentice mechanic, I am still on very good terms with the owner, and whenever I need anything checking or plugging in to diagnostics, he always lets me pop in and have it done for free, as it only takes a few minutes. 

The TT pipe came off as you said it would... a little bit of a tricky bugger, but I did as you said, and wedged a plastic card under one of the arms, and then pronged the other two out, and it just popped off. Super easy to put the Toureg one on, literally just _pop_ and it was on. Super careful with the removal of the pipe end from the valve cover and it was a doddle as they say.

Stay tuned for the before and after of the screw fitting, I will make sure I keep you up to date on the source 

Man I am so happy right now. Thinking about the hours of frustration pulling all that front end out to take the inlet off, and forking out for a complete cylinder head cover just to replace a palm sized piece of rubber really was a downer on what was meant to be the happy purchase of a new car!


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## Magnus32

Just ordered some of these from RS Components...

RS PRO Clear Passivated, Zinc Steel Pan Head Self Tapping Screw, M3 x 5mm Long
Stock no.:483-1202


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## SwissJetPilot

That is such great news! Really happy this worked out. [smiley=thumbsup.gif]

I think long term, when it come time for pulling the valve cover for some other service, it would be a good idea to open up the COS and remove the spring and diaphragm. Over time, I can imagine it will continue to degrade so no point leaving it in there indefinitely.

But yeah, thanks again for your willingness to give this a try. Super news that it's worked out. 

Now I need to get myself an *M4* screw and keep it in the trunk (boot). With my luck, when my PCV fails, it will be on a Sunday morning and miles from home! :lol:


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## Magnus32

Absolutely, I'll probably end up removing it at some stage later down the line, depending on what I end up doing with the TT, if I fall in love with it, maybe some faster cams and full exhaust system 😉

Hahaha, I am thinking of keeping the ebay one in the boot when it comes, instead of returning it, just in case!


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## SwissJetPilot

It would be interesting to know if *Automotion Components Ltd* has a self tapping version of the M4 available to you guys in the UK.

Automotion Components Ltd
Alexia House
Glenmore Business Park
Portfield Works
Chichester, PO19 7BJ (UK)

Telephone 0333 207 4498
or + 44 (0) 1483 266 774
Email [email protected]


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## Magnus32

They would be good for purpose. The RS ones should be good. I'll stick a little 3mm ID O-ring around it and whack some gasket paste on for good measure.


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## scot360

I have ordered the VW part for £120 but I still see this as good value compared to actually changing the diaphragm in the rocker cover.
I try and avoid third party parts if I can.
I have tried to fit so many incorrectly supplied parts in my lifetime, wasted many hours etc. Doing the job twice.
I am very glad it worked for Magnus32.

I am away with work until Friday so I cannot fit it until then.
I am very grateful to Magnus32 and SwissJetPilot for the information.

What a brilliant modification.


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## Magnus32

Update - Still running all fine and dandy, MPG has increased A LOT. Must of been dumping tonnes of fuel in to correct the mixture.

Good luck with it Scot, hope all goes well


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## SwissJetPilot

@ *Magnus32* - You should now have PM access.

Is the fuel consumption a result of the Toureg PCV swap (still happening now) or was it going on while the TT diaphragm was broken and leaking air through the vent hole (happened in the past)?


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## Magnus32

Oh sorry, I mean it has vastly improved since fitting the Toureg valve.
When I was driving with the defective diaphragm my mileage was awful!


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## scot360

I have fitted the Toureg part.
I think it looks good.
Blocked up the hole with a screw and some thread lock that fills 0.5mm gaps so I am happy.

Tick over all back to normal and no hissing of air being pulled in so its all good.


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## SwissJetPilot

@ *Magnus32*  
@ *scot360* 

Thanks guys, for proving this works.


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## Magnus32

Thank you for providing us with the knowledge!


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## Magnus32

JOY!


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## SwissJetPilot

Just a reminder, if you have access to a VCDS or OBDeleven, you'll want to clear any fault codes that came up when the diaphragm failed and leaked. Then run another scan just to make sure everything's good.


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## custard

Many thanks SwissJetPilot for this fix.

The PCV diaphragm failed on my my 2007 3.2 in 2019 and i had to replace it the conventional way.

Unfortunately it failed again recently and i was not looking forward to having to open the cover again to replace. It hadn't thrown any fault codes and the revs were ok this time, but i could feel the vacuum on the relief hole and when removing the oil filler cap on idle. Luckily i found this thread and was able to apply the alternative fix. The car is working well and the filler cap only has a slight vacuum pressure now.

When blocking the the relief hole on the cover i found that an M3 would not engage the aluminium but would engage the inner plastic. This did not tap in very well though.
So i used a M4 instead which engaged the aluminium but i was only able to inset to about 2mm. The fit is tight and i have used *Loctite 243 (Blue)* to seal it further.


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## SwissJetPilot

@ *custard* - Thanks for the update. That's valuable information.  I've updated the previous comments to recommend an *M4 x 5*. From the looks of your installation, it only needs about 3-5mm of thread length to engage and seal properly.

If you would be so kind, be sure to come back in a few months or few thousand miles and let us know how it's working out. A long term performance review would be great.

One other note, keep in mind you're screwing a steel screw into an aluminum valve cover. Long term there could be a potential for galvanic corrosion between the dissimilar materials. But the use of *Loctite* should minimize it.

If possible, you might want to look for an M4 aluminum screw of the same pitch. Since the steel screw has already cut some partial threads into the hole, the aluminum screw should go in quite easily. Looking at the *Loctite 243* literature, it's compatible with aluminum so won't be an issue.

*Screws Compatible With Aluminum*

When aluminum and stainless steel are used in an assembly together, the electrons from the aluminum will begin to transfer into the stainless steel. This results in the aluminum weakening. This weakened aluminum causes it to deteriorate at a much faster rate. Audi goes deep into this topic in *SSP 383* *Audi TT Coupe Body & Assembly.*

*Aluminum Screws*
Because galvanic corrosion happens when dissimilar metals come into contact with each other, the simplest way to prevent the process is to use screws made from the same metal as the metal you're fastening. Aluminum screws will not cause corrosion in aluminum base metal, even if the screws aren't plated or treated with any corrosion-resistant material.

*Carbon Steel Screws*
Unplated steel screws will cause corrosion in aluminum in a wet environment. They'll rust quickly themselves, as well, so they're not a good choice for fastening aluminum. Galvanized steel screws, however, are plated with a corrosion-resistant coating, usually consisting of zinc, that is not nearly as reactive with aluminum. The zinc plating prevents the underlying steel from coming into contact with the aluminum, and the risk of corrosion of the aluminum is reduced significantly.

*Stainless Steel Screws*
Stainless steel is an alloy of carbon steel that is, itself, resistant to corrosion. However, stainless steel is reactive with aluminum, and when a stainless steel screw is in contact with an aluminum base metal, the aluminum is likely to corrode. As is the case with carbon steel screws, a plated stainless steel screw is less likely to corrode aluminum; screws treated with a high-quality coating consisting of zinc and aluminum flakes are especially resistant to corrosion.


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## custard

@SwissJetPilot

I did go for the passivated screws so hopefully that should help as well.
https://uk.rs-online.com/web/p/self-tap ... s/4831224/

I will take your recommendation and see what aluminium screws i can find.


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## SwissJetPilot

@ *custard* - For the short term a passivated screw should be fine. But long term, no sense asking for trouble.

Aluminum screws might be tricky to find at the local hardware store, but a specialty hardware (industrial) or eBay or Amazon.

You can even try a local hobby store since aluminum screws are quite popular with RC cars and they sell them in small packs. Check these UK hobby shops and run a search for "aluminum screws" -

MB Models | radio control cars, from bashing to race
RC Cars, Remote Control Cars and Radio Controlled Cars from Modelsport UK


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## custard

Here's the aluminium screw in place. Bought *M4 x 6mm* black anodized off eBay.


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## SwissJetPilot

Well done!


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## MT-V6

Just me being picky, but I think it would look a lot nicer cut down so that the head sits flat against the surface


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## custard

Hi MT-V6. Maybe some day I'll get the hacksaw out and reduce the length of the screw. I have one spare aluminium screw to play with. Would rather prefer to screw-in further instead but that has proved difficult.


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## SwissJetPilot

Normally a hole should be tapped before inserting a non-self tapping screw, but I'm a bit wary of the small metal bits that could end up inside the valve cover. In this case however, it might be enough to create some internal threads with a steel M4 screw as the thickness of the valve cover at this location is only about 3-4 mm. Then remove the steel screw and insert the aluminum screw with a dab of blue *Loctite 243* on the threads. Given the wall thickness of the valve cover an *M4 x 5* should be sufficient.


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## davidpribyl

Hello,
I tried to use the Touareg PCV, but motor is still whistling.
So I decied to change original membrane (dismantle valve cover).
Or I speculate to get out original membrane and put only Touareg PCV (I leave the original small hole sealed).
It is possible to leave the engine without original membrane and have only Touareg PCV?
Thanks.


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## SwissJetPilot

As shown in the previous images, if you hear the whistle from the vent hole, that means the internal PCV diaphragm has failed. The whistle is due to air leaking through the ruptured diaphragm and out the vent hole.

In order for the Toureg PCV to work, you'll have to use an *M4 x 5* screw to block the vent hole.

Keep in mind this vent hole is only there to allow the diaphragm to move up and down (see diagrams on previous pages). In normal operation the diaphragm blocks the vent. However when the diaphragm splits, then you'll end up with a vacuum leak.


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## davidpribyl

Yes, I did it the same way you write. 
Only instead of the M4x5 screw, I sealed the hole with aluminum sheet and no air escapes here. 
Before I put the Touareg PCV, the original PCV whistled at idle all the time, even when accelerating. Now only if I accelerate a lot.
The engine may be sucking in false air somewhere, but how do I find out?


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## SwissJetPilot

@* davidpribyl - *Pay attention to any vacuum lines that look cracked and around where they connect to something as they often split at the ends. There are a number of different methods for finding a vacuum leak. You can search the forum for "vacuum leak" to see if anyone else has had a similar problem. Or check *Youtube* for various methods. The process for searching for a vacuum leak is generally the same for any engine.


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## TheonZ

@SwissJetPilot you are genius! I was struggling with this issue, my rough idle was horrendous. I came across this forum and saw your solution. I gave it a try and saved myself £800, the only thing I struggled with was fitting the m4 screw in the redundant breather hole, apart from that, no more rough idle or crazy revs etc!


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## SwissJetPilot

@ *TheonZ *- Glad it worked out for you!  At some point you may want exchange that steel screw for an aluminum one to prevent any galvanic corrosion (steel and aluminum don't play well together). The steel screw will already have cut the threads into the vent hole, so the aluminium one should go in easily. A little dab of blue Loctite never hurts. Hobby stores that sell RC parts often have aluminium screws, or you can order them off eBay or Amazon.


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## EosVR6

Thanks for the tutorial.
I have a VW Eos with the same engine (BUB), I had the same symptoms.
The car had air leak problems, lambda sensor problem, unstable idle, too lean mixture in 3 cylinders, heavy smoke from the exhaust with a powder smell.
I tried several miracle products, changed spark plugs, coils, until I came across your forum.
I just tried the solution with the VW Touareg valve and everything is back to normal.
The car is working normally again, I still removed the coils and spark plugs which I cleaned with a wire brush and after erasing all the faults with the VCDS everything is now normal.
A big thank you for this forum and all the contributors! It saved me expensive expenses to open the engine block.


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## SwissJetPilot

@ *EosVR6* - Excellent!


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## Spadge

Hi all,

Just wanted to say thanks to Swiss Jet Pilot for this excellent hack. Probably the best money saving car hack I've ever come across due to the simplicity of the installation Vs the relatively labourous alternative (removing valve cover, etc)

My car started whistling on the way home from an overnight trip a week or two ago. At first it sounded like a screeching and I suspected a blet slipping or bearing going. By the time I got home it had stopped and I didn't have time to look at it so I sought of crossed my fingers and hoped for the best.

A couple of days later when I was out, the car developed a rough idle. The revs kept searching between 700rpm and 1500rpm and the EPS light came on.

The next day I tried to set off for work and there was a strong smell of fuel like the TT was running rich and I had to keep the revs up or it would stall. I parked her up and took the wife's car to work.

Later I came across this post when researching what could be the cause. Anyway I decided to try the method laid out here.

For the record I opted to go with the Febi Bilstein 47564 that another member here suggested. The part did fit but I snapped one of the mounting lugs off when trying to fit it, so current it is only held on by two, but it is working.

Based on my experience I would not recommend using the Febi Bilstein replacement. If you compare the Febi model below to the image of an alternative below it you will notice one of the lugs is profiled with a cut out in it. I believe this cut out is necessary to prevent snapping during installation. I have ordered an alternative el cheapo model via AliExpress in order to test the theory and will update once I have it fitted.

Also, for the record, I tapped the breather hole to M4 with a tap wrench and fitted an M4 stainless caphead screw with 246 loctite, with a anti rattle washer plus an M4 washer. I have an aluminium M4 screw on order to replace the stainless one with to prevent galvanic reaction 😉

Overall though this is an amazingly simple solution to an overcomplicated Audi problem.

Bravo!!!!

Febi Bilstein model








El cheapo AliExpress model (note the profile of the lug in the foreground)


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## SwissJetPilot

@ *Spadge* - Glad that worked out! 


Spadge said:


> Also, for the record, I tapped the breather hole to M4 with a tap wrench and fitted an M4 stainless caphead screw with 246 loctite, with a anti rattle washer plus an M4 washer.


 Would be great if you could post a picture of your valve cover with this arrangement. And again when you get your aluminum screw.

Looking at the mounting stand-offs on the manifold I hadn't noticed these features before. I'm assuming this is why you cut the notches in the "AliExpress El Cheapo" tabs. That's great information and I have updated my post to include a comment regarding non OEM PCV and that trimming the clip may be necessary to ensure it fits properly to avoid breaking it.


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## Spadge

SwissJetPilot said:


> Glad that worked out!
> Would be great if you could post a picture of your valve cover with this arrangement. And again when you get your aluminum screw.
> 
> Looking at the mounting stand-offs on the manifold I hadn't noticed these features before. I'm assuming this is why you cut the notches in the "AliExpress El Cheapo" tabs. That's great information and I have updated my post to include a comment regarding non OEM PCV and that trimming the tab may be necessary to ensure it fits properly to avoid breaking the tab.
> View attachment 482383
> 
> View attachment 482384


Yes those are the features that caused me the issue I think. Did you use an official VW part and did it mount ok with these features?

For the record I did not trim my tabs. That's probably why one snapped. I noticed that one of the tabs is profiled on the AliExpress option, which may be done to account for the feature. For the sake of £15 for the part I thought I'd order one to see if it's a better fit.


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## SwissJetPilot

The one I ordered from Amazon is a made by *Vierol AG* and it fit perfectly as noted in my earlier posts *here* and *here*.
According to the *7zap parts *website Part Number *022.103.765A* and *022.103.245B* are used on a number of 6-cylinder engines; AZZ, BMV, BAA, BMX, BKJ, and BRJ for both the Touareg and Phaeton.


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## TT_A4

Thank you for this tip. I had to replace the diaphragm and was holding off on the job. With this fix, I ran the Febi part and eventually got it on. It's a tight fit, and I trimmed the centering tab a bit. But eventually the PCV snapped into place. I found that a 6-32 screw fit better for me. But you know us Yanks. =) No more whistling and after the car had a chance to run and idle for a while the engine smoothed out at idle. 
The great is that this saves tons of time and effort. The bad is that the cover gasket is a bit old and starting to leak, but hey I will keep an eye on that and see how it goes.


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## dennyfmn

Thanks to SwissJetPilot clueing me in to this fix, I was able to repair my 2008 Quatro Roadster with a broken PCV diaphragm. I bought a *022.103.765A* from AutoZone locally here in Minnesota for just over $100. It was the least expensive part I could get locally; the VW dealer quoted over $200. It only took overnight to get the part to my local store. It's all installed already and the engine is running _much_ better. I suppose it will take a while driving it to let the ECM fine tune the mixture now that the air leak has been repaired.

I found it a bit challenging to get all three clips freed up at the same time to remove the old part. I finally used a thin screwdriver and slipped pieces of a cut up credit card into the crack. I did something different to seal the leaking vent hole. I had a roll of 3M High Temperature Flue Tape that is supposed to be good to 600 degrees F. I thoroughly cleaned the casting with isopropyl alcohol and the tape seems to be adhering nicely. I'll let you folks know if this does not hold up.


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## SwissJetPilot

Hopefully that high temperature tape holds up, but otherwise well done!


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## Luca17as

Dear SwissJetPilot, could you please confirm that this hack can last as original configuration ? Is there any problem leaving the damaged rubber of the old pcv ?


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## SwissJetPilot

As far as I know, it shouldn't be an issue. Depending on how long you keep the car, you will have to pull the valve cover eventually in order to have the timing chain and tensioners replaced. At that point I would remove the internal OEM diaphragm completely since it's totally unnecessary and just keep using the Touareg PCV.


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## Jjmorris90

I’m attempting this repair. Ordered the part waiting for it to be delivered. I didn’t even realise anything was wrong until it was pointed out to me. The loud whistling rough idle etc.

I’m enjoying this car as my little project. I brought it for £1000 from a friend. It’s a 2007 3.2. It was stood for quite some time. Changed all the pads and discs and brake lines. Now to tackle this and then service it!


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