This bulletin provides information when there is increased oil consumption; >0.5ltr/1000 km.
full bulletin at NHTSA ↗2015 Audi S6 engine problems
severe 3 complaints filed with NHTSA · avg repair $3,100 · see engine across all vehicles →
When does it fail?
Of the 3 engine complaints filed for the 2015 Audi S6, here's the actual mileage breakdown — failures cluster heaviest at 50,000-75,000 mi.
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
Of the 5 model years of Audi S6 we track for engine problems, this one has the fewest owner complaints on file (3).
No new NHTSA engine complaint has been filed on this vehicle in over 4 years — the issue may be aging out of the active population.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
This bulletin provides informaiton when the engine is not running smoothly, misfiring.
full bulletin at NHTSA ↗This bulletin provides information on VIN Plates, Safety Certification labels, and the ordering procedures.
full bulletin at NHTSA ↗This bulletin provides information on the use of the Audi frequencly analysis app, and where the application can be downloaded.
full bulletin at NHTSA ↗This bulletin provides information regarding UV leak additive for finding oil leaks.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
What owners are reporting 3 most recent
Turbos blew causing the vehicle to lose power while trying to merge in traffic.
Multiple turbo failures. Engine shook violently then suddenly stopped in the middle of the road. This same issue happened 3 times affecting both turbos. It may be due to faulty oil filter/strainer. From online research (link below) this is a common problem for C7 Audi s6. https://www.audizine.com/forum/showthread.php/851578-2016-S6-4-0T-Turbo-Failure
Driving on the new jersey turnpike and both turbochargers failed. Car lost power and I had to steer to side of the highway without power steering and brakes from far left lane. Audi service says bearings starved of oil and seized. They said this is a common problem with the 4.0 twin turbo Audi engines and that the oil feed line gets blocked and starves the turbochargers of oil, resulting in…
Common questions
How serious is the engine problem on the 2015 Audi S6?
It's a meaningful issue. 3 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $3,100.
At what mileage does the engine typically fail?
Based on the 3 complaints filed, engine issues most often appear around 69,500 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.