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2011 Touareg Excessive Oil Consumption and the PCV

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23K views 27 replies 9 participants last post by  blue5t1053  
#1 ·
Over the past year or so my vehicle has been "burning" more and more oil. It would go through about a quart in 1000 miles. I looked into causes of oil burning or excessive oil consumption, and found it could likely be the PCV membrane in these vehicles. I replaced it a few days ago, but I'm down another bar in about 200 miles after the upgrade, so it does not appear to be much better. The old membrane appears to be stretched out, but it was not torn.

I'm assuming the PCV is the culprit, considering there was a ton of oil in the breather tube, as well as in the throttle body (which i'm assuming isn't normal operation). I still dont have any engine codes, so I dont think I did the replacement incorrectly, but I didnt have any codes or rough idling prior to that either. I pulled the breather tube connection off and saw there was still some oil in the tube after replacement.

Is there anything else with that system that can be faulty? Should I just buy an entire new valve cover with the PCV housing in it? I also see the breather tube has some sort of connector on it, does this have anything to do with the PCV or oil separating system? If anybody has any insight to the subject, I would appreciate it.

Pictures of the breather port/tube with oil in it, and the old PCV Membrane attached
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#2 ·
We own a 11 VR6 and a 09 A4 with 2.0T engine, the Audi engine has a huge multi page thread on the B8 A4 forum in the www.audizine.com website. https://www.audizine.com/forum/showthread.php/383430-THE-B8-A4-Oil-Consumption-Thread

When a B8 A4 has excessive oil consumption the first thing checked is the PCV to make sure it is the updated version (not sure if any updated version in VR6 is available) and after that the dealer begins a documented consumption test that ends up costing the owner about $500 minimal. If it is verified that the 2.0T engine is consuming excessive amounts of oil the engine is pulled and new piston and rings are put in. It appears the weep holes in the piston and oil ring were undersized and the oil ring did not put enough pressure against the cylinder wall, the small weep holes get clogged up over time (IMO can be attributed to 10K OCI) and the oil that is lubricating the cylinder wall is not draining back into the oil pan on down stroke and burning off in the combustion stroke. Tell tale sign oft this is tailpipe having excessive black soot around outside edge of where exhaust exits. You can also take a white t-shirt and stretch ac cross tailpipe and have someone rev the engine a dozen times. If oil burning off through combustion the t-shirt will be black.

Think about this, why was the OCI on VW/Audi's 5K when it was recommended service when we paid for it and as soon as VW/Audi included it in basic maintenance it became 10K..............

My A4 had pistons and rings replaced and I do 5 to 7K OCI max on both Touareg and A4 with high quality Ravenol oil I get online, keeping my fingers crossed because we usually keep our cars to 200K and an engine rebuild is not happening on my dime.
 
#3 ·
Thanks for the reply. I definitely have excess black soot around the tail pipe, but is there a way to tell if that is due to piston rings or from the PCV? I know that there is oil being pumped back into the intake from the PCV breather tube that is eventually going to get sucked in to the cylinders and burned off, which would also cause soot around the pipe.

How many miles did you have on your car when you replaced the pistons and rings? Did you do it yourself, and did it solve the problem?

Sorry for all the questions, but I'd love to find a fix for this instead of dumping a quart out the exhaust every couple weeks! Its otherwise a great running vehicle.
 
#8 ·
the PCV is under the valve cover, as an integral part to the cover. I watched a few videos on youtube for removing the cover, and RKX that sells a replacement membrane does a great video on replacing it. Although the valve cover video is a Passat, It is the same engine that is in my car only it is turned 90 degrees in the engine bay. Links below:

valve cover removal:
membane replcaement:
 
#5 · (Edited)
You should address the PCV first, that is what Audi does before they begin the oil consumption test. With the amount of oil you showed in the tube I would think that could be the source of your oil consumption or at least a really good starting point.
Can PCV be purchased by its self ? What is current P/N and Rev of PCV you have and what Rev is the part now from VW ?
Is the PCV built into the Valve Cover ? If so they are on Rev L now
Valve Cover - Volkswagen (03H-103-429-L)
 
#9 ·
I have already replaced the membrane, but there is still oil in the tube and there hasn't been much improvement with consumption. There is a company that sells just the replacement membrane, but Im wondering if there is something else with the system that is not functioning correctly. The PCV should also have a way of collecting the vaporized oil and returning it into the engine (and not sending it into the intake). I may just end up buying the new cover with a whole new PCV, in case something is clogged/dirty in that housing and not allowing the oil vapors to collect and drain.
 
#12 ·
It should have suction on the intake manifold side, the purpose of PCV is to recirculate the crankcase vapors back into engine combustion chamber to be burned off, this is part of the emissions system. Excessive oil in tube IMO would be a faulty PCV or excessive crankcase pressure forcing oil pass the valve.
On my 70 GTO the PCV was on the valve cover and looked kinda like a mushroom, let crankcase vent into the open without any recirculation back into combustion chamber.



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#14 ·
Bob, thanks for your reply regarding the vacuum lines. I see that your oil consumption problems appear to be fixed. I guess I missed the beginning of the thread, so I have a few questions.
I'm assuming you were experiencing high oil consumption problems, How did you fix it? and also, regarding the dipstick, where did you purchase it, and where does it go?
The only place that looks like a dipstick tube on mine is on the right side of the engine, but the top of it appears to be shut with the same material as the tube.

Thanks,
Ray
 
#16 ·
I don't think my higher than what I thought should be normal oil consumption was related to the PCV but possibly dirty return holes in piston for oil lubricating cylinder walls. I ran an oil additive for (2) 5K mile oil changes and now seems to be back to normal.
There is a cap that you can remove where you indicated on engine, then I got dipstick online that fits 2010 Passat with 3.6 VR6 engine, had to put my own marks on at 6L and 7L fill points.
When I get time my plan is to check the PCV breather line for oil and will post back. Pretty sure there should be minimal oil if any in that tube so your next step would be either replacing diaphram or getting new valve cover from VW with new PCV installed.
 
#19 ·
Doing it now. I came across another problem. A broken plastic piece that connects to the intake-manifold on the right side. Looks like some type of vacuum that actuates a flap that separates the midpoint between the cylinder intakes. I don't know if I broke it when I was taking the intake-manifold off, or if it was already broken and causing the jutter/misfire under load/when I hit the gas really hard.
Any idea what that is?
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