2015 Audi S4

The 2015 Audi S4 is a performance-oriented sedan that was part of the B8.5 generation. It came standard with a supercharged 3.0-liter V6 engine producing 333 horsepower and 325 lb-ft of torque. This engine was paired with either a 6-speed manual or a 7-speed S-tronic dual-clutch transmission. Owners generally appreciate the S4’s responsive engine, sporty handling, and comfortable interior. However, some common complaints include higher maintenance costs compared to non-luxury brands and potential issues with the car’s electronic systems.

Engine

3.0L Supercharged V6

• Carbon Buildup
  • Description/Symptoms: Direct injection engines like the 3.0T can experience carbon buildup on the intake valves, leading to rough idling, decreased performance, and poor fuel economy.
  • Solution: Walnut blasting or chemical cleaning of the intake valves to remove carbon deposits.
  • Estimated Cost to Fix: $600 - $1,200+
  • Recalls: None Found
• Water Pump Failure
  • Description/Symptoms: Leaking coolant, overheating, and a warning light on the dashboard.
  • Solution: Replacement of the water pump.
  • Estimated Cost to Fix: $500 - $900+
  • Recalls: None Found
• Thermostat Failure
  • Description/Symptoms: Overheating, coolant leak, or not reaching operating temperature.
  • Solution: Replace thermostat.
  • Estimated Cost to Fix: $400-$700+
  • Recalls: None Found
• Supercharger Coupler Failure
  • Description/Symptoms: Rattling or knocking noise from the supercharger, loss of boost, and reduced engine performance.
  • Solution: Replacement of the supercharger coupler.
  • Estimated Cost to Fix: $300 - $600+
  • Recalls: None Found

Transmission

6-Speed Manual

• Clutch Failure
  • Description/Symptoms: Clutch slippage, difficulty shifting gears, and a burning smell.
  • Solution: Clutch replacement.
  • Estimated Cost to Fix: $1,200 - $2,000+
  • Recalls: None Found

7-Speed S-Tronic (Dual-Clutch)

• Mechatronic Unit Failure
  • Description/Symptoms: Harsh or jerky shifting, delayed engagement, and error messages on the dashboard.
  • Solution: Replacement or repair of the mechatronic unit.
  • Estimated Cost to Fix: $2,000 - $4,000+
  • Recalls: None Found
• Clutch Pack Failure
  • Description/Symptoms: Slipping during acceleration, shuddering, and difficulty shifting.
  • Solution: Replacement of the clutch packs.
  • Estimated Cost to Fix: $3,000 - $5,000+
  • Recalls: None Found

Suspension

• Control Arm Bushing Failure
  • Description/Symptoms: Clunking noise from the front suspension, uneven tire wear, and vague steering.
  • Solution: Replacement of the control arm bushings or entire control arm assembly.
  • Estimated Cost to Fix: $300 - $800+ per control arm
  • Recalls: None Found

Electrical

• Adaptive Headlight Malfunction
  • Description/Symptoms: Headlights not leveling correctly, error message on the dashboard.
  • Solution: Diagnosis and repair or replacement of the headlight control module or the headlight assembly itself.
  • Estimated Cost to Fix: $500 - $1,500+
  • Recalls: None Found
• Power Window Regulator Failure
  • Description/Symptoms: Window moving slowly, erratically, or not at all. Clicking sound when operating the switch.
  • Solution: Replacement of the window regulator.
  • Estimated Cost to Fix: $300 - $600+ per window.
  • Recalls: None Found

Exterior

• Fog Light Cracking
  • Description/Symptoms: Cracks in the fog light lenses, often due to rock chips or temperature changes.
  • Solution: Replacement of the fog light assembly.
  • Estimated Cost to Fix: $200 - $400+ per fog light.
  • Recalls: None Found

Interior

• Navigation/MMI System Issues
  • Description/Symptoms: System freezing, slow response times, or failure to boot up.
  • Solution: Software update, replacement of the MMI control unit.
  • Estimated Cost to Fix: $500 - $2,000+
  • Recalls: None Found

In summary, the 2015 Audi S4 is a generally reliable performance sedan but can be prone to certain issues. The most common problems revolve around the engine (carbon buildup, water pump), transmission (mechatronic unit failure in S-Tronic), and electrical systems. Repair costs can range from a few hundred dollars for minor issues to several thousand for more complex problems like transmission or engine repairs. Potential buyers should be aware of these potential issues and factor them into their purchasing decision.