Tap a category to read its complaints. One report may name several components.
When problems were reported
Mileage at the reported incident
Limited mileage data: 0 of 1 reports include usable mileage. There isn’t enough coverage to show a useful chart.
NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.
What to inspect
Issues worth paying extra attention to based on owner reports.
Engine. Review the 1 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
NHTSA owner reports · September 18, 2026 snapshot.
0 crash reports0 fire reports0 injury reports
What owners actually said
1 reports
Mileage unknown · Jan 13, 2023
Engine
The R&R valve/oil separator unit failed on my 2015 Audi S4 at approximately 71,000 miles. This unit, when fails, can mix the oil and anti-freeze which can seize the engine. I was able to catch the problem before engine failure. Minneapolis Audi repaired the vehicle this week, 1/10/23. There were NO warning indicators except …
Read full complaint
The R&R valve/oil separator unit failed on my 2015 Audi S4 at approximately 71,000 miles. This unit, when fails, can mix the oil and anti-freeze which can seize the engine. I was able to catch the problem before engine failure. Minneapolis Audi repaired the vehicle this week, 1/10/23. There were NO warning indicators except noise. Various media sources have stated that this is a known engine failure concern between 60-90K miles for this engine. Audi does not recognize this as a safety or warranty concern.
Volkswagen Group of America, Inc. (Volkswagen) is recalling certain model year 2013-2015 Audi A4 and S4 vehicles manufactured February 16, 2012, to October 21, 2014, and 2013-2015 Audi Allroad vehicles manufactured March 12, 2012, to October 21, 2014. Due to an improper algorithm in the air bag control module, if a crash necessitates deployment of the side air bags, a second impact to the front of the vehicle may not command the front air bags to also deploy.
Consequence & remedy
Consequence: If the front air bags do not deploy in the event of a secondary impact to the front of the vehicle, there is an increased risk of occupant injury.
Remedy: Volkswagen will notify owners, and Audi dealers will update the air bag control unit software, free of charge. The recall began on November 14, 2014. Owners may contact Audi customer service at 1-800-822-2834. Volkswagen's number for this recall is 69K5.
Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗
NHTSA investigations
0
No exact-year investigations in this snapshot.
2015 Audi S4 Problems, Complaints & Recalls | Skip That Year
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