Oil Consumption and things to try to resolve the issue.

[EuroxS4]

Hey guys, so many of you may know that audi did have an extension for 10years/100k miles for oil consumption on 3.0T supercharged engines. Some of you may know I purchased a a6 with a badly over heated engine a few years back which was then torn down,the heads were decked and the block was checked and milled true as well as checked if it was out of round or not. Turned out it was all good after being milled true. All has been well up until now. At this point I have put on about 15k miles on this engine without any issues other than, It is starting to eat some oil. About a quart ever 1000miles.

My car is out of the extension because of time as most of your vehicles will be as well. The main issue which is responsible for oil consumption is oil being burned in the combustion chamber either because of piston to wall clearances being too big or piston rings not sealing and letting oil into the chamber. So long story short audi had redesigned pistons and piston rings installed into later engines after 2012 model year. Earlier cars if you were lucky enough to get them done within the extension had engines torn down and pistons and rings replaced. For me right now a engine pull and tear down is not possible/feasible due to time constraints.

Common cause is carbon buildup in the rings causing this issue. This past wednesday I put in some BG EPR before changing the oil. So for this particular engine I made sure it was up to operating temp first, put 2 cans of EPR in. Ran it as per their instructions roughly 1200rpms for 10 minutes, then drained the oil. After that changed the oil filter. Refilled with new oil and added 2 cans of BG MOA to the oil,and refilled the engine and set the oil level. Time will tell what the results will be but I have been using BG products for some time and they do work. I know alot of people will say its snake oil and so on, most of the nay sayers are people who tried to use a particular product after it was too late for it to do anything as most of their products are meant to be used as a preventative measure.

In either case I will keep you guys updated as to what the outcome is. I am logging the mileage and will most likely change the oil within the next 2500miles anyways and do another flush before doing so. If anyone has any experience with this common issue feel free to comment below if you have used other products with good results. It would be good to compile a list of products as options as well as have some factual data behind it to see what works and what is just a waste of time.

[MTL4]

I haven’t used the BG EPR/MOA combo on my Audi (I use the Liquimoly engine oul flush myself with great results) but I have used BG44k extensively when I was a mechanic and it’s definitely good stuff. Obviously there’s a few different ways you could be using oil (one being piston rings) and another big one on the 3.0T is the PCV system so make sure that has been addressed on your engine as well. Lastly I would highly suggest taking before and after (roughly a week apart) compression test readings on all the cylinders especially if you believe it to be a piston ring issue (with higher compression indicating better ring sealing). This should tell you how well each product worked or if you have some other mechanical issue causing problems.

[11A6]

from what I've read on this and other forums as well as some pretty extensive youtube tear downs, there are other ways these engines burn and/or leak oil beyond the rings and the PVC. There is the tensioner covers on the back. It's also been reported that some of the 09's may have had a main bearing go. personally I think one of the leading culprits but also the hardest to see/document is that the engine is built in layers and between the layers are either sealants or gaskets. the 3.2 & the 3.0 (which the 3.0 block is based off)has a cam girdle level which is sealed by an anerobic sealant and like over time they can leak. One possible sign is if you look in spark plugs you may see leaks towards the bottom of those and that could be a sign that that cam girdle sealent is leaking. Look for videos on you tube from KK or Kelisko - re his a6 with 3.2 that he's built back up after finding oil leaks. Keep us posted.

[MTL4]

Often when you see oil at the bottom of the spark plug holes on the 3.0T it’s usually a valve cover gaskets (had to replace both sides on mine too, super crispy and leaking badly). Other leaks like timing cover and rear main seal should have clearly visible external signs on the back/underside of the engine (esp if the leaks are significant enough to change your engine oil level over a short period of time).

[EuroxS4]

Being that the engine was completely torn down and redone by me, I have already checked that there are no external leaks anywhere on the engine. Yes oil leaks do occur on every engine ever made. However external leaks and oil consumption are 2 totally different scenarios/issues, that being said these engines do burn oil. The goal here is to try to find a remedy to cut down and minimize oil consumption without a engine overhaul.

[MTL4]

That’s why I mentioned above that any oil leak big enough to change your oil level in a short period of time is going to be very obvious. Oil consumption on the other hand shows no visible signs since it’s being burnt in the combustion process. Definitely get a baseline compression test on your motor so you know where you started if your oil consumption begins to drop.

[EuroxS4]

Already done 185-195psi on all cylinders roughly 5% leak down so she looks like shes in spec. I guess well find out.

[rich84]

Have this issue myself with 1L oil being burned between 1500 and 4000km depending on oil being used. I have found Castrol Edge Titanium to be the worst for oil consumption so far, although I'm sure it is a good quality oil.

I have replaced the PCV valve which made no difference at all. Failing that I expect to tear the engine down and find inadequate flow through the oil control rings due to carbon build up. Same issue as 2.0T just to a lesser extent.

I have leaks around my rear timing covers but not enough to even drip on the ground let alone create an oil slick large enough to cover litres of oil.

[EuroxS4]

Have this issue myself with 1L oil being burned between 1500 and 4000km depending on oil being used. I have found Castrol Edge Titanium to be the worst for oil consumption so far, although I'm sure it is a good quality oil.

I have replaced the PCV valve which made no difference at all. Failing that I expect to tear the engine down and find inadequate flow through the oil control rings due to carbon build up. Same issue as 2.0T just to a lesser extent.

I have leaks around my rear timing covers but not enough to even drip on the ground let alone create an oil slick large enough to cover litres of oil.

Ive been using Castrol Edge 5w40. Recently switched to Total quartz 9000 5W-40. This oil meets the specs, yet has also been proven to help cut down on carbon inside the engine as it contains more detergents in it as it is used in diesel engines as well. Diesel engines a far more dirtier on the inside compared to gasoline engines, so using a oil with more detergents in it wount hurt. We will see what happens. I have a trip coming up thats going to be roughly 900miles round trip I will report with results.

[rich84]

Ive been using Castrol Edge 5w40. Recently switched to Total quartz 9000 5W-40. This oil meets the specs, yet has also been proven to help cut down on carbon inside the engine as it contains more detergents in it as it is used in diesel engines as well. Diesel engines a far more dirtier on the inside compared to gasoline engines, so using a oil with more detergents in it wount hurt. We will see what happens. I have a trip coming up thats going to be roughly 900miles round trip I will report with results.

Mine only really seems to use oil in traffic and under heavy acceleration I can see a light smoke haze in the rear view at night if there's a car behind me. Cruising it does not seem to use any - I've done a 5000km road trip and used no oil. YMMV though.

[PPETKOV]

Ive been using Castrol Edge 5w40. Recently switched to Total quartz 9000 5W-40.

Here are my 2 cents: Forget about Catrol Total, Motul and so on mainstream OIL-s. I would go for Redline 5w40. You have it at quite good price in USA. Here in Europe it cost double therefore I'm using Ravenol RCS 5w40.
My oil consumption for 10k km is about half liter (~ 1/2 quart). The car is with JHM Stage 2 I drive mainly on highways and country roads ~ 10% in city.

The deal with the mainstream engine oils is that they are sold as Synthetic while in reality they are based on Oil group III/III+ ...

btw: What is the P/N of the PCV valve that you have installed ?

p.s. Lubegard have one of the top engine flushes.

[rich84]

I'll probably try a few more things before thinking about replacing the pistons and rings. Top end cleaner may be worth trying and I'll try different oils as so far my experience points to oil type being a significant factor in the consumption. Uses more than double the oil when I use Castrol Edge Titanium 5w30 vs Penrite HPR5 5w40. If oil flow through the piston/oil control ring becoming restricted is the culprit for the oil consumption on these engines, you'd think the thinner oil would reduce oil consumption, not the other way round.

Part no for my PCV valve was 06E103547AC.

[squirrels]

I feel it necessary to mention in this thread that even a liter of oil consumption per 1000 km should not be a cause for major concern in most cases... If an engine doesn't appear to consume oil, I am instantly concerned because I will immediately assume that the consumed oil is being replaced by fuel. What you should do is simply track the oil consumption over time, and if you see a relatively sudden change in oil consumption (i.e. over a period of one or a few oil changes) without any major environmental/driving habit changes, only then is it time to start looking for what's changed.

[B. Rock]

Also worth noting is that the oil rating is more important than the brand or viscosity when it comes to consumption, assuming the problem isn't valve stem seals anyway.

The euro blend oils that are VW approved have different ash levels that impact how the oil performs in the combustion chamber of forced induction, direct injection engines. I saw oil consumption get cut in half moving away from regular mobil 1 over to the euro blend, or the proper liqui moly (don't remember the exact blend). There's a whole thread on this somewhere in this forum with the details.

[rich84]

I feel it necessary to mention in this thread that even a liter of oil consumption per 1000 km should not be a cause for major concern in most cases... If an engine doesn't appear to consume oil, I am instantly concerned because I will immediately assume that the consumed oil is being replaced by fuel. What you should do is simply track the oil consumption over time, and if you see a relatively sudden change in oil consumption (i.e. over a period of one or a few oil changes) without any major environmental/driving habit changes, only then is it time to start looking for what's changed.

The main issue I'd be concerned about is the oil control ring getting so clogged with coked oil that it starts scoring the cylinder walls. Because these are nikasil lined cylinders, at least in my country I don't believe that there's a shop that can machine and re-line these bores. We know this does happen with the 2.0T, which has the same cylinder design as the 3.0T - if the issue is allowed to progress far enough (I'm talking 1L burnt per 200-300km type oil usage, which to date I have not seen with the 3.0T). I'm not too concerned with mine as long as it stays less than 1L per 1500km. The last litre lasted me 3000km.

[EuroxS4]

That whole nikasil BS only applies to stock pistons and rings. I have many of these engine bored to a bigger size with aftermarket pistons and rings and run without any sort of oil consumption issues. That being said. The car is still consuming oil. After 3 oil changed roughly 2k miles apart and using the EPR product. But it seems as its not as bad. I am considering doing a engine flush with bg products to see if the results will get any better. However at this time I am more focused on some other repairs the car needs. Like flex pipes for the exhaust as some genius audi engineer thought it was a good idea to make that part of the exhaust 1 piece along with the catalyst. No thanks not paying 3 grand a pop for cats over some flex pipes when I can weld in some quality aftermarket flex pipe.

[squirrels]

That whole nikasil BS only applies to stock pistons and rings. I have many of these engine bored to a bigger size with aftermarket pistons and rings and run without any sort of oil consumption issues. That being said. The car is still consuming oil. After 3 oil changed roughly 2k miles apart and using the EPR product. But it seems as its not as bad. I am considering doing a engine flush with bg products to see if the results will get any better. However at this time I am more focused on some other repairs the car needs. Like flex pipes for the exhaust as some genius audi engineer thought it was a good idea to make that part of the exhaust 1 piece along with the catalyst. No thanks not paying 3 grand a pop for cats over some flex pipes when I can weld in some quality aftermarket flex pipe.

Dude... What?? You don't bore out an audi alusil block unless you sleeve it.... And I have never seen someone who actually wanted to go through that, it's cheaper to just get another block. Or are you talking about boring out some nikasil bore from a different manufacturer on a cast iron block???