V6t B8 Oil Consumption

[Tom Ashby]

Evening Ladies and Gents,

I’ve owned my V6t 2011 S5 for about 5 weeks now and it had a major service at Audi Coulsdon the day before I picked it up. Since owning the oil level has gone from 90% on the digital bar to now at about 40%. I have noticed what I think is steam/vapour from the exhaust but thought this was maybe due to the weather. Do these suffer from oil consumption? I’ve done roughly 5/600 miles in these 5 weeks. Car is sitting on 54000 miles.

Any input/advice appreciated.

 

[MuPPeT_ON_TouR]

They do not suffer from that amount of consumption. Done a little over 2k in mine since I got it and oil hasn't moved. 2014 plate.

You definitely have a fault.

 

[Tom Ashby]

They do not suffer from that amount of consumption. Done a little over 2k in mine since I got it and oil hasn't moved. 2014 plate.

You definitely have a fault.

Any idea what would cause to burn oil ? Getting a bit frustrated now as the first S5 I bought I rejected due to timing chain issues, now I’ve bought this one I’m having this

 

[Dippy]

If you have ruled out gasket problems (e.g. oil in the coolant) then its likely either going to be piston rings or crankcase ventilation. Unlike what happened on the 2.0TFSI of a certain date range, there does not seem to have been design-related piston ring oil leakage problems on the 3.0TFSI. Nevertheless any engine can suffer from poorly seated rings, possibly caused during the early life of the engine when the components were new. However there have been enough reports of PCV valve problems with this engine to suggest that it is the #1 likely cause of the problem.

 

[Tom Ashby]

Dippy, thanks.

Forgive my limited knowledge, what is the PCV valve problem. I’m still under warranty with the dealer I bought the car from so I need to get this sorted pretty quick. If this is the issue, will it deteriorate and cause major damage/failure?

 

[Dippy]

The "positive crankcase ventilation" system allows the gasses which pass from the piston combustion past the rings and into the crankcase (these are very small leaks which are inevitable) to escape safely. The system is designed to recycle the gasses and also any oil from vapours that come too. The PCV valve ensures that the gasses only pass from the crankcase into the system and not the other way round. If it gets stuck open it causes problems, including possible oil leaks. I admit I don't fully understand exactly why but just that it does. The bottom line for you is that unfortunately there have been sufficient reports of PCV valve failure on our 3.0TFSI engine to believe that it is a "known" point of failure. if it affects yours then yes it needs to be replaced as soon as possible and indeed it should be covered by your warranty.