2018 Audi S4

The 2018 Audi S4 is a performance sedan known for its blend of luxury, technology, and exhilarating driving experience. It came standard with a 3.0-liter turbocharged V6 engine producing 354 horsepower and 369 lb-ft of torque. This engine was paired exclusively with an 8-speed automatic transmission (Tiptronic). Owners typically praise the S4’s responsive engine, sharp handling, and comfortable interior. Common dislikes include the somewhat muted exhaust note compared to rivals, and the potential for expensive repairs as the car ages.

Engine

3.0L Turbocharged V6 (EA839)

• Thermostat Housing Leak
  • Description/Symptoms: Coolant leaks from the thermostat housing, often accompanied by a low coolant warning light and the smell of coolant.
  • Solution: Replace the thermostat housing and gasket.
  • Estimated Cost to Fix: $400 - $800+
  • Recalls: None Found
• Water Pump Failure
  • Description/Symptoms: Overheating, coolant leaks, and potentially engine damage if not addressed promptly. The water pump impeller may fail.
  • Solution: Replace the water pump.
  • Estimated Cost to Fix: $800 - $1200+
  • Recalls: None Found

Transmission

8-Speed Automatic (Tiptronic)

• Rough Shifting/Hesitation
  • Description/Symptoms: Jerky or delayed shifts, particularly between lower gears. Some owners report hesitation when accelerating from a stop.
  • Solution: In some cases, a software update or adaptive learning reset can improve shift quality. In more severe cases, valve body replacement or transmission rebuild may be necessary.
  • Estimated Cost to Fix: $200 (Software Update) - $4,000+ (Rebuild)
  • Recalls: None Found

Suspension

• Adaptive Damper Malfunction (If Equipped)
  • Description/Symptoms: Error messages related to the suspension system, uneven ride quality, and noticeable clunking noises from the suspension.
  • Solution: Diagnose the specific damper and wiring. Replacement of the faulty damper is typically required.
  • Estimated Cost to Fix: $800 - $1500+ per damper
  • Recalls: None Found

Electrical

• Infotainment System Freezing/Crashing
  • Description/Symptoms: The MMI (Multi Media Interface) system may freeze, crash, or become unresponsive.
  • Solution: A software update is often the first step. If that doesn’t resolve the issue, the MMI unit itself may need replacement.
  • Estimated Cost to Fix: $100 - $300+ (Software Update), $1200 - $2500+ (MMI Unit Replacement)
  • Recalls: None Found
• Sensor Failure (Parking Sensors, Driver Assist)
  • Description/Symptoms: Parking sensors may become unreliable or stop working altogether. Driver assist features (e.g., lane keep assist, adaptive cruise control) may display error messages or malfunction.
  • Solution: Diagnose the specific sensor and wiring harness. Replacement of the faulty sensor is usually required.
  • Estimated Cost to Fix: $300 - $800+ per sensor
  • Recalls: None Found
• Battery Drain
  • Description/Symptoms: The car’s battery drains quickly, especially when the car sits for a few days, leading to starting problems. This can be exacerbated if aftermarket electronic accessories are installed.
  • Solution: Identify parasitic draw by testing the electrical system. Fix any circuits that have high draw when the car is off. Test the battery. Replace battery.
  • Estimated Cost to Fix: $100 (electrical testing), $200 - $500 (battery), $200-$1000+ (repairing faulty wiring)
  • Recalls: None Found

Exterior

• LED Tail Light Failure
  • Description/Symptoms: Sections of the LED tail lights may fail, resulting in reduced visibility.
  • Solution: Tail light assembly replacement.
  • Estimated Cost to Fix: $500 - $1000+ per tail light assembly
  • Recalls: None Found

Interior

• Sunroof Issues
  • Description/Symptoms: Sunroof may get stuck in one position, or not want to fully close.
  • Solution: Sunroof calibration, or replacement of the sunroof motor.
  • Estimated Cost to Fix: $100 - $300 (calibration), $500 - $1500+ (motor replacement)
  • Recalls: None Found

Summary

The 2018 Audi S4 is generally a reliable vehicle, but certain issues are more prevalent than others. Engine cooling system components (thermostat housing, water pump) and electrical glitches in the infotainment system and sensors seem to be the most commonly reported. Transmission issues, while less frequent, can be quite expensive to resolve. The severity of these issues ranges from minor annoyances to potential engine damage, and the cost of repairs can vary significantly depending on the specific problem and the shop performing the work. Prospective buyers should be aware of these potential issues and have the vehicle thoroughly inspected by a qualified mechanic before purchasing.