The 2014 S5 with the 3.0T supercharged V6 is generally solid, but catastrophic engine failures from carbon buildup and oil consumption plague higher-mileage examples, often requiring complete rebuilds. The dual-clutch transmission (S tronic) has its own oil cooler and mount weaknesses that need attention.
Catastrophic Engine Failure from Carbon Buildup and Oil Consumption
Occasional · high severity
Typical onset: 80,000-130,000 mi
Symptoms: Excessive oil consumption (1 qt per 1,000 mi or worse), Misfires, rough idle, loss of power, Check engine light for multiple cylinder misfires, Catastrophic failure: knocking, seized pistons, spun bearings
Fix: Direct injection causes intake valve carbon buildup leading to poor sealing and oil burning past rings. If caught early, walnut blasting valves and new PCV can help (4-6 hours), but advanced cases need full engine rebuild or short block replacement (25-35 hours labor). Pistons, rings, bearings, and sometimes crankshaft damage from oil starvation.
Estimated cost: $12,000-18,000
Transmission Oil Cooler Failure
Common · high severity
Typical onset: 60,000-100,000 mi
Symptoms: Transmission fluid leaking from front of vehicle, Overheating transmission, hard shifts or slipping, Transmission warning light
Fix: The auxiliary transmission oil cooler develops leaks at seals or cracks internally. Requires removal and replacement of cooler unit plus complete transmission fluid flush. 3-5 hours labor. Ignore it and you cook the dual-clutch mechatronic unit ($5k+ additional).
Estimated cost: $800-1,400
Transmission Mount Failure
Common · medium severity
Typical onset: 70,000-110,000 mi
Symptoms: Clunking on acceleration or deceleration, Excessive driveline vibration, Visible transmission sag or torn rubber mount
Fix: The rear transmission mount tears and allows excessive drivetrain movement. Simple replacement but requires supporting transmission on jack. 2-3 hours labor. Often replaced alongside engine mounts.
Estimated cost: $400-700
Thermostat Housing Coolant Leak
Occasional · medium severity
Typical onset: 60,000-90,000 mi
Symptoms: Coolant smell in engine bay, Visible leak at front of engine, Low coolant warning light, Overheating if ignored
Fix: Plastic thermostat housing cracks or o-rings fail. Must replace entire housing assembly and sometimes coolant flange. 3-4 hours labor with front-end disassembly for access.
Estimated cost: $600-1,000
Supercharger Snout Bearing Failure
Rare · high severity
Typical onset: 90,000-140,000 mi
Symptoms: Whining or grinding noise from front of engine, Noise increases with RPM, Check engine light for boost pressure faults, Complete loss of boost if bearing seizes
Fix: The front bearing on the supercharger input shaft wears out. Requires supercharger removal and rebuild or replacement. 8-12 hours labor. Can grenades and send metal through intake if it catastrophically fails.
Estimated cost: $3,000-5,000
PCV System Failure Leading to Oil Leaks
Common · low severity
Typical onset: 50,000-90,000 mi
Symptoms: Oil residue around valve covers, Oil consumption without visible leaks, Rough idle, Whistling or hissing from engine bay
Fix: Diaphragm in PCV valve fails, causing crankcase pressure issues and pushing oil past gaskets. Replace PCV valve and associated hoses. Often done with valve cover gaskets. 4-6 hours labor if doing full job.
Estimated cost: $800-1,400
Owner tips
Change oil every 5,000 mi max with quality synthetic (0W-40) and monitor consumption religiously — catch oil burning early
Walnut blast intake valves every 40,000-50,000 mi to prevent carbon buildup ($400-600)
Service dual-clutch transmission fluid every 40,000 mi despite Audi claiming 'lifetime' fill
Budget $1,000-1,500/year for maintenance beyond oil changes once past 70,000 mi
Pre-purchase inspection MUST include compression test and borescope inspection of cylinders
Buy one with full service history under 60,000 miles or expect to budget for a potential engine rebuild — when they're good they're great, but engine failures are too expensive to gamble on high-mileage examples.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.
Fitment notes: AGM required for start-stop system; battery located in trunk under cargo floor
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Every control module on the 2008-2016 Audi S5 — where it lives, replacement time, and what it takes to program a replacement. Modules marked dealer / factory tool won't work after a part swap alone — budget for programming.
📍 Rear trunk lid, integrated in trunk handle or license plate area
🔧 VCDS or Autel
⚠️ Optional equipment. Calibration for parking guidelines may be needed.
Aftermarket tool coverage varies by software version and vehicle build — treat "aftermarket tool" rows as "usually possible" and verify against your tool maker's coverage list before promising a customer. Spot a wrong location or hour? Tell us — corrections ship fast here.
Size-standard part numbers — verify your connector type before buying. Rear blades are model-specific; check the package's vehicle list.
Fuel economy figures are EPA data via fueleconomy.gov (median across matching trims). Performance figures are compiled estimates for the 2014 Audi S5 3.0L Supercharged V6 and can vary by trim.
🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years and Jeff Moore · Master Lexus & Toyota Mechanic · 20+ years.