Buying a Used Audi S8 D4: Reliability Guide and What to Watch Out For
The Audi S8 (D4 generation, roughly 2012–2018) blends super-sedan performance with luxurious limousine refinement. Powered by a 4.0-liter twin-turbo V8 (EA825/EA824), the S8 offers both brutal acceleration and long-distance comfort. But, as a high-performance flagship, its maintenance needs can be demanding — and certain weak points are well-documented. Below is a comprehensive guide to help you evaluate a used S8 D4 from a reliability perspective.
Overall Reliability of the S8 D4
-
The S8 D4 is generally considered relatively robust for a V8 twin-turbo super-sedan, thanks to a well-engineered 4.0T engine and a durable ZF 8-speed transmission.
-
Many of the reported problems relate to engine oil consumption, turbo wear, and complex cooling systems, rather than catastrophic mechanical failure. (MyEngineSpecs.com)
-
According to recent Technical Service Bulletins, Audi has recognized “engine oil consumption too high” on V8 4.0 TFSI models and has introduced updated piston rings for production.
-
A pre-purchase inspection (PPI) is strongly recommended. As one buyer guide states: if you skip details like turbo condition or oil system, you risk very costly repairs.
Common Problems with the S8 D4
-
Excessive Oil Consumption
-
Frequently reported by S8 owners.
-
Causes include piston ring wear, valve seal degradation, and turbo seal leaks.
-
Audi’s updated piston rings address this in some newer or later-production models.
-
If oil level gets too low, engine damage is possible — regular top-ups and checks are vital.
-
-
Turbocharger Failures / Oil Supply Blockage
-
The 4.0 V8 has its turbos mounted in the engine “hot V,” which generates extreme temperatures.
-
There’s an oil screen in the oil supply module; if it clogs, the turbos can be starved of oil, which is the number-one risk for turbo failure on this engine.
-
A 2020 NHTSA Technical Service Bulletin noted impeller damage or turbo shaft play in some 4.0T units.
-
-
Carbon Buildup on Intake Valves
-
Due to direct injection, carbon deposits can accumulate on intake valves over time, causing misfires or rough running.
-
Regular walnut blasting or intake cleaning is recommended to maintain performance.
-
-
Cooling System / Overheating Risk
-
Water pump and thermostat housing can leak, particularly in older or high-mileage S8s.
-
Cooling components in high-performance use (or aggressive driving) may be stressed.
-
-
Air Suspension Faults
-
Many S8s have adaptive (air) suspension, which can develop leaks, sagging, or compressor failure.
-
Repairing or replacing air springs or compressors can be costly.
-
-
Electrical & Sensor Issues
-
MMI infotainment system may glitch or freeze.
-
Sensors for driver-assistance systems (e.g., radar, cameras) may fail or need recalibration.
-
-
Timing Chain / Tensioner Wear
-
Some reports mention tensioner wear or rattling on cold start, though this is less common than oil or turbo issues.
-
Upgrade and Customize Your Audi S8 D4
Personalize your S8 D4 with premium, performance-inspired accessories. Add a black Audi badge, carbon-fiber mirror caps, or interior carbon trims to intensify its sporty look.
Upgrade the interior with CarPlay retrofit modules, carbon trim kits, and paddle shifter extensions for that true driver feel.
All parts are crafted for precise OEM-style fitment, and every product ships for free with a 1-year warranty — so you get both style and peace of mind.
What to Inspect When Buying a Used S8 D4
-
Confirm full service history, especially oil change intervals.
-
Ask for turbo maintenance records or whether the oil supply screen was cleaned or revised.
-
Perform a cold-start test and listen for unusual rattling (timing chain or tensioner).
-
Check oil level before and after a test drive — note if it drops significantly.
-
Inspect suspension ride height to detect sag or air-spring failure.
-
Validate that MMI and infotainment systems are fully functional.
-
Scan for fault codes relating to PCV, turbo pressure, or valve anomalies.
-
Prefer cars with moderate mileage and documented care — ideally by an Audi specialist.
Verdict: Is the Audi S8 D4 Reliable Enough to Buy Used?
Pros:
-
Powerful and refined 4.0L twin-turbo V8
-
Strong and proven automatic transmission
-
Quattro drivetrain adds robustness and traction
-
Potential for long life when well maintained
Cons:
-
High running costs: oil consumption, turbo maintenance, and possible suspension repairs
-
Complex systems (air suspension, electronics) that can fail or need expensive parts
-
Risk increases significantly with neglected maintenance
Conclusion: A well-maintained Audi S8 D4 can be a very rewarding performance luxury car. If you find one with documented service history, particularly for oil and turbo system maintenance, it's a strong candidate — but budget for its maintenance needs.