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Quick update - i have over 6000 km on the car since the repair and it has not consumed a drop of oil. Prior to the repair, I was adding 1 litre every 4,000 km - clearly the repair made a difference.
Two minor problems related to connectors not being assembled completely - easy fix and dealer dealt with them right away.
UPDATE: My car is in for a corporate-mandated pistonectomy. There's a new piston design and it seems like a lot of the early cars will be so "privileged".
That really sucks! I'm hoping I'm not one of the "privileged". I've put about 8k miles on mine since I bought it and it's not consuming oil so I think that's a good sign.
UPDATE: My car is in for a corporate-mandated pistonectomy. There's a new piston design and it seems like a lot of the early cars will be so "privileged".
Hmm that stinks but interesting update.
From Audiusaparts:
Manufacturer: Audi
Part Number: 079-107-066-EM
Part: Piston
Replaces: 079-107-066-EG, 079-107-066-DT
I assume your piston part number is one of the old ones (EG or DT) and now you are getting EM. Would be interesting if you could confirm.
That really sucks! I'm hoping I'm not one of the "privileged". I've put about 8k miles on mine since I bought it and it's not consuming oil so I think that's a good sign.
Mine didn't consume any oil either. The symptoms, as with the OP for this thread, are a flashing CEL that occurs upon restart (usually, but not always, a cold start). The plugs on one or two cylinders are fouled with oil and have to be cleaned or replaced. Not sure why it's only intermittent (it's only happened twice in 48,000 km), as I would have thought a faulty piston or ring design/installation would cause continuous issues.
Originally Posted by gk1
Hmm that stinks but interesting update.
From Audiusaparts:
Manufacturer: Audi
Part Number: 079-107-066-EM
Part: Piston
Replaces: 079-107-066-EG, 079-107-066-DT
I assume your piston part number is one of the old ones (EG or DT) and now you are getting EM. Would be interesting if you could confirm.
They haven't ordered the parts yet, but I will confirm once I get the car back, along with all the paperwork. Right now, I've only had a glance at Audi's unofficial "fix-it" guide for this issue. Also, nothing about the updated oil check valve/screen that seemed to be so critical to the OP's recent fix. I have brought that part to the tech's attention.
Well, the front of my car, along with the engine, is in little bitty pieces. Definitely not a sight for the faint-of-heart. I can report that there is a little bit of carbon build-up on the intake valves, but nothing like the RS4 was prone to.
Gpinard, THANK YOU FOR POSTING THIS! I am currently experiencing the EXACT same issue that you were experiencing. Cylinder 8 misfires on my 2013 S7, and the spark plug has been observed to be dripping in oil, causing the misfire. As soon as a new plug is installed (same idea to your dealer removing the oil), my car works absolutely perfectly... Until the oil fouls the spark plug again that is.
My main question for you: did your fix end up working for you long term? I see the update at 6,000km, but I'm curious how long after you had without issues?
For context, my S7 has 145,000km, and is coincidentally also a Canadian car from Toronto, although I currently use it in Edmonton. I've been having this sporadic misfire for about 20,000km. I think there might be something to the theory of this being a cold weather problem. My car also has very good compression test results just like yours.
One thing I can say is that the fix for your car definitely was not the oil check valve that you were talking about. This check valve in your pictures (#3) is the turbo oil supply line check valve:
The role of this valve is to ensure that when your car turns off, the oil in the lines going to the turbo do not drain. If this valve didn't work, on cold starts your turbos would have very little oil, and would eventually wear out the turbo bearings. There's no logical way this valve could cause oil to enter the cylinder. Funny enough, I actually replaced this valve about 20,000km before any of my issues occurred while I was upgrading my turbos, since I was in there anyways. So it's definitely not the issue.
However, I'm curious if there's a chance this is not the actual valve they are talking about. Perhaps there was a miscommunication and they're actually talking about the coarse oil return check valve? This is unlikely, because I checked the valve on your parts list and it seems to be the exact one I replaced under the turbos.
Interestingly, the note at the bottom here says that it could cause oil consumption, and thus oil would burn in the cylinder.
Assuming that your fix was indeed a permanent fix, it seems as though the solution is either the piston rings or the valve stem seals, because the check valve under the turbos wouldn't help. Unless of course, they replaced the coarse oil check valve using the same part. That could definitely explain it.
Once again, thanks for posting your progress! It has given me lots of valuable info in the search for my fix!
Gpinard, THANK YOU FOR POSTING THIS! I am currently experiencing the EXACT same issue that you were experiencing. Cylinder 8 misfires on my 2013 S7, and the spark plug has been observed to be dripping in oil, causing the misfire. As soon as a new plug is installed (same idea to your dealer removing the oil), my car works absolutely perfectly... Until the oil fouls the spark plug again that is.
My main question for you: did your fix end up working for you long term? I see the update at 6,000km, but I'm curious how long after you had without issues?
For context, my S7 has 145,000km, and is coincidentally also a Canadian car from Toronto, although I currently use it in Edmonton. I've been having this sporadic misfire for about 20,000km. I think there might be something to the theory of this being a cold weather problem. My car also has very good compression test results just like yours.
One thing I can say is that the fix for your car definitely was not the oil check valve that you were talking about. This check valve in your pictures (#3) is the turbo oil supply line check valve:
The role of this valve is to ensure that when your car turns off, the oil in the lines going to the turbo do not drain. If this valve didn't work, on cold starts your turbos would have very little oil, and would eventually wear out the turbo bearings. There's no logical way this valve could cause oil to enter the cylinder. Funny enough, I actually replaced this valve about 20,000km before any of my issues occurred while I was upgrading my turbos, since I was in there anyways. So it's definitely not the issue.
However, I'm curious if there's a chance this is not the actual valve they are talking about. Perhaps there was a miscommunication and they're actually talking about the coarse oil return check valve? This is unlikely, because I checked the valve on your parts list and it seems to be the exact one I replaced under the turbos.
Interestingly, the note at the bottom here says that it could cause oil consumption, and thus oil would burn in the cylinder.
Assuming that your fix was indeed a permanent fix, it seems as though the solution is either the piston rings or the valve stem seals, because the check valve under the turbos wouldn't help. Unless of course, they replaced the coarse oil check valve using the same part. That could definitely explain it.
Once again, thanks for posting your progress! It has given me lots of valuable info in the search for my fix!
Hi woodepic
I no longer have the car - I traded it in early 2019 with about 110,000km on it. I think I can call the fix a "permanent fix" as there was no recurrence of the problem. I am afraid i cant tell you much more on the check-valve . . . i understand your skepticism of the diagnosis and root cause but I am relying on the feedback from Audi. My problem started when the car sat for an extended period of time and the oil was only in cylinder #8 - that lead me to believe it was a unique problem with that cylinder and it was something than allowed oil to run down in to the cylinder after it was turned off which is why my original suspicion was valve stem seal. I understand how improperly installed piston rings can lead to oil consumption but can not make the connection to oil pooling on the piston as the ring bypass would occur when the engine was running and thus the oil would burn off. Having said all of that, these engines are much more sophisticated than when i used to tear motors apart so it is entirely possible there is a connection that i am not seeing. They took so much apart and changed so many parts that it is really hard to know which part/repair really solved the problem - all i know for sure is the problem didnt come back and the oil consumption seemed to be reduced - piston rings and valve stem seals may be the true solution but who knows . . .
Okay thanks for the info! Yeah that definitely sounds like it was a permanent fix. It just seems like an awfully large coincidence that these cars all seem to have the same issue on cylinder 8.
I plan to design an oil separator delete in order to rule out the possibility of oil entering the intake that way.I will look into this more, and keep the forum updated if I find anything! Thanks for your help and all the info!
06-25-2016, 06:40 PM
