2018 Audi RS6 Problems: 2 Issues Every Owner Should Know
2018 model year · NHTSA recalls, manufacturer TSBs, and owner forum reports · Updated May 2026
According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2018 Audi RS6 has 2 documented known issues. No issues are rated critical, indicating generally reliable ownership. Across all issues, repair costs range from $800 to $2,000. DIY maintenance guides at au7o.io.
All 2 Known Issues
On the 2013-2023 Audi RS6 4.0T V8, the 4.0T twin-turbo V8 in RS6, RS7, and RS Q8 suffers from severe carbon buildup on intake valves due to direct injection. The high-performance nature and twin-turbo setup means carbon accumulates faster than in lower-output engines. Over 60,000 miles, carbon restricts airflow causing rough idle, misfires, and power loss. The V8 configuration requires removing both intake manifolds, making walnut blasting more expensive ($1,200-$2,000) than 4-cylinder engines. RS6.com forums recommend cleaning every 60,000 miles as preventive maintenance. Failure to clean can cause valve damage requiring expensive cylinder head work on the $120,000+ RS models.
Common Symptoms
- Rough idle
- Hesitation on acceleration
- Power loss
- Poor fuel economy
- Check engine light with misfire codes
- Engine runs rough when cold
How to Fix
WALNUT BLASTING: Remove both intake manifolds and blast walnut shells through all intake ports ($1,200-$2,000 for V8). Repeat every 60,000 miles. PREVENTION: Install catch can ($500-$800 for twin-turbo setup). Add Liqui Moly Intake Valve Cleaner to every oil change. Change oil every 5,000 miles. Drive car hard regularly.
What Owners Are Using
Parts and tips from 0+ owners who fixed this issue
- TipWalnut blasting is the primary solution for 4.0T carbon removal. Hot-V layout makes this more labor-intensive than standard engines. Budget $1,000-$2,000 for professional service.
- TipRegular high-RPM driving helps burn off some deposits. The 4.0T hot-V layout creates additional heat challenges that accelerate carbon accumulation.
- UpgradeNo widely-available direct-fit catch can kit exists for the 4.0T hot-V. Mishimoto Universal Baffled Catch Can (MMBCC-UNI-BK) can be adapted with custom brackets. (Mishimoto #MMBCC-UNI-BK)
- NoteCarbon deposits on 4.0T can prevent proper valve closure, leading to compression loss and misfires. Address rough idle promptly with borescope inspection.
On the 2013-2023 Audi RS6 4.0T V8, the RS6, RS7, and RS Q8 with 4.0T V8 engines experience premature motor mount failures due to the engine's high torque output (600+ lb-ft). Motor mounts wear out between 40,000-80,000 miles, causing excessive engine movement, vibrations, and clunking noises during acceleration or deceleration. The high-performance nature of RS models accelerates mount wear compared to base models. Failed mounts cause driveline stress and can damage other components. RS246.com forums report this as a common issue on high-mileage RS models. Replacement costs $800-$1,500 for all mounts.
Common Symptoms
- Vibrations at idle
- Clunking noise during acceleration or deceleration
- Excessive engine movement visible from engine bay
- Transmission shifter vibration
- Steering wheel vibration
- Rough shifting
How to Fix
Replace failed motor mounts with OEM or upgraded mounts ($800-$1,500 for all mounts). Upgraded aftermarket mounts (034 Motorsport, ECS) offer better durability for high-torque engines ($400-$600 per mount). If you drive aggressively or track the car, consider upgrading to performance mounts preventively. Monitor for vibrations and clunking—early replacement prevents driveline damage.
What Owners Are Using
Parts and tips from 0+ owners who fixed this issue
- UpgradeOEM motor mounts from FCP Euro with lifetime warranty. The 4.0T V8 produces extreme torque that tears OEM mounts prematurely, especially on tuned cars. (Genuine VW/Audi Engine Mount (4.0T V8))
- Upgrade034 Motorsport density-line motor mounts provide stiffer mounting that resists deformation better than OEM rubber. Reduces drivetrain slop and improves throttle response. (034 Motorsport Density-Line Motor Mounts)
- TipSymptoms of failed mounts: excessive engine movement visible under hood, clunking during gear changes, vibration at idle. Easy visual inspection - look for sagging or torn rubber.
- NoteFailed motor mounts allow the engine to shift, which can damage exhaust manifolds, turbo lines, and wiring harnesses. Replace promptly when symptoms appear.