Austin1982

I had the same issue with my 2009 Audi A4 2.0T, purchased it brand new and by the time it had 50,000 miles the oil consumption increased dramatically. I asked the dealer for all "technical bulletins" issued on the vehicle. Once I asked this question they acknowledged there is one and did an oil consumption test which showed one quart lost every 600 miles. They ultimately (with a little prodding) took responsibility for the issue with the piston rings (improper size from a supplier) and replaced in the vehicle at no charge. I am surprised this is still coming up as an issue, but the major word at the dealer is technical bulletin. They have to provide all or any related to issue on your specific engine type.

kelisko

A periodic flush is probably a good idea but that won't clean up the exhaust valves. This engine has a problem of excessive carbon buildup which would eventually cause exhaust valve failure if the rings don't give up first. When I pulled my supercharger intercoolers at 148K miles, what I saw in there was crazy! My 2005 Audi A6 3.2 FSI with over 200K miles did not have even half of that carbon contamination in the upper intake manifold (old style non-motorized supercharger).

Ktran350

Correct. But isn’t the root cause the piston rings? If someone doesn’t have consumption currently or if someone had their engine replaced, valves cleaned,…etc, use this flush method as a periodic maintenance item, shouldn’t it alleviate some of not all future consumption concerns? If we are able to clean/keep clean the piston rings thus in return keep the exhaust valves clean and minimize oil consumption?

kelisko

Your argumentation makes sense. A periodic flush keeping the rings clean may help limit oil consumption which in return may "limit" valve contamination. However, the level of carbon contamination with this engine is already high without the rings issue because of poor engine ventilation as discussed in other threads in this forum. Saving this engine will require, beside the periodic engine flush, a better blow-by management solution like an oil catch can and a modification allowing the engine's bank 1 to be ventilated as well because it is not, which is silly engineering.

Ktran350

Thanks. I’ve read those threads. I’ll give this a shot. I’m due for my next oil change soon. Just figured some solution to slow down consumption is better than no solution. Might look into valve cleaning as well.

2kwik4u

@GlennR @keg97 @petery129@mhoran89 @TheBudgetBaller @silver_tt @kelisko

Updating the log again (new data in red). As I'm driving more, the data is coming in faster!

• 97,118mi - Changed and full - 2023-09-25
• 99,616mi - added 1qt, light on - 2,498mi since last fill - 2023-10-17
• 102,594mi - added 1qt, light on - 2,978mi since last fill - 2023-11-18
• 103,604mi - added 1qt, light on - 1,010mi since last fill - 2023-12-07
• 104,454mi - added 1qt, light on - 850mi since last fill - 7,336 since last change - 2023-12-24

2024 Data

• 105,105mi - added 1qt, light on - 651mi since last fill - 7,987 since last change - 2024-01-03
• 105,140mi - Changed oil. 5W-40 Liqui-Moly, Fresh Filter - 2024-01-13
• 107,534mi - added 1qt, light on - 2,394mi since last fill - 2,394 since last change - 2024-02-04
• 108,928mi - Added 1qt, light on - 1,394mi since last fill - 3,788 since last change - 2024-02-25 (Castrol GTX "Euro" 5W-40 oil from AutoZone)
• 110,562mi - Changed oil, 5W-40 Castrol GTX "Euro" 5W-40, fresh filter - 1,634 since last fill - 5,422 since last change - 03-09-24 (Light came on as I was pulling into the parts store)
• 112,461mi - Added 1qt, light on - 1,899mi since last fill - 1,899 since last change - 2024-03-18 (Castrol GTX "Euro" 5W-40 oil from AutoZone)

This quart was like 99% highway driving with cruise set around 75-80mph. Buffalo to Louisville three times (Up, Back, and Up again). Car still pulls well, and is returning 22-24mpg on long interstate trips. Going to hit 30k miles of driving this year at this rate. Ugh.

Does look like Liqui-Moly held out about 500 miles MORE on the first quart as compared to the Castrol GTX. Super small sample size of 1 here, but it's something. I do see a definite trend of the oil usage being less during the front half of the oil change interval. Likely speaks to the need to keep fresh oil in it. Curious if those (I'll have to go back and read) that don't have consumption issues did better with faster OCI's as compared to those that followed the longer Audi recommendations. I have a theory that tighter OCI's on the front end will prevent the oil control ring "caking" issue, and make this a non-issue from the start. I suspect it's far less to do with the PCV than we think. Secondarily, those running aftermarket tunes where the supercharger clutch stays locked, also have a lower consumption rate, as you're in boost more often than those of us on stock tunes. This has a direct effect on cylinder pressures, and the ability for the oil to get past the rings to begin with. Lots of conjecture there, I know.

More details as they arise.

MoInEd

I have always (on all my vehicles) changed oil more frequently than recommended. I think there has been a push to have larger oil reservoir to require less frequent service to keep customers happier (at the cost of shorter life-span for the car).
Data gathered here suggests it might be a good practice to keep going.
I have never used additives or products to flush engine or clear build up as discussed here. Is Liqui-Moly the more popular one to help with this oil consumption issue as the engine ages?

kelisko

What I noticed when I used Liqui-moly engine flush is that there is apparently no sludge on engine components that are lubricated by the engine oil. I poured in new oil and installed a new oil filter before adding the Liqui-Moly solution. After running the engine for 15 or so minutes, the oil came out relatively clear enough and the filter looked fine. I proceeded to a second flush with fresh oil and filter again right after the first one and the oil came out even clearer. This makes me think that engine flush will do nothing to this problem. The issue is isolated to the combustion chamber and related components. A piston soak may help free the piston rings but there is no guarantee. Then carbon contamination of other components in the intake and exhaust system may cause worse issues like a burnt exhaust valve. I documented step by step my experience in the video below. It's an A7 but it's the exact same engine.

MoInEd

Thanks, that makes sense that most of the build-up is in the combustion chamber and hence the oil additives shouldn't help much with those (maybe there are fuel additives/cleaners to help with that?!).

Ktran350

I doubt it since the MPI injectors only spray on the intake valves. Best bet based on what I’ve read here is that once you notice oil consumption is to check to make sure your PCV valve is still good and replace it if it isn’t, engine flush and a B12 soak. That should bring the rings back to where it should be and continue the flush as preventative maintenance every so many miles.