2016 Mercedes-Benz SL550

The 2016 Mercedes-Benz SL550 is a luxurious roadster known for its blend of performance and comfort. It comes standard with a powerful 4.7-liter twin-turbo V8 engine producing 449 horsepower and 516 lb-ft of torque. Other options were not available from the factory. The transmission paired with the SL550 engine is a 9G-TRONIC 9-speed automatic transmission. Owners often praise the SL550 for its smooth ride, refined interior, and effortless power, while some criticisms include the complex electronics, potential for costly repairs, and somewhat dated infotainment system.

Engine

4.7L Twin-Turbo V8

• Oil Leaks
  • Description/Symptoms: Oil leaks can develop from various points in the engine, including valve cover gaskets, oil filter housing, and turbocharger oil lines. Symptoms include visible oil leaks, oil consumption, and burning oil smell.
  • Solution: Replace the leaking gaskets or seals. Tighten or replace loose or damaged oil lines.
  • Estimated Cost to Fix: $200 - $1,500+ depending on the location and severity of the leak.
  • Recalls: None Found
• Turbocharger Issues
  • Description/Symptoms: The turbochargers on the 4.7L V8 can experience issues such as wastegate failure or oil leaks. Symptoms include reduced power, whistling or grinding noises from the engine, and potential oil consumption.
  • Solution: Replace the faulty turbocharger(s).
  • Estimated Cost to Fix: $2,500 - $5,000+
  • Recalls: None Found

Transmission

9G-TRONIC 9-Speed Automatic

• Rough Shifting/Hesitation
  • Description/Symptoms: Some owners have reported experiencing rough or delayed shifting, particularly between lower gears. This can manifest as a noticeable “clunk” or hesitation during acceleration.
  • Solution: A software update to the transmission control module (TCM) may resolve the issue. In some cases, replacing the valve body or the entire transmission may be necessary.
  • Estimated Cost to Fix: $200 (software update) to $5,000+ (transmission replacement).
  • Recalls: None Found

Suspension

• Air Suspension Malfunctions (ABC - Active Body Control)
  • Description/Symptoms: The SL550’s Active Body Control (ABC) air suspension system can be prone to leaks in the hydraulic lines, pump failure, or strut failure. Symptoms include a sagging suspension, uneven ride height, warning lights, and a harsh or bouncy ride.
  • Solution: Replace leaking hydraulic lines, the ABC pump, or faulty struts. Flush the ABC system fluid.
  • Estimated Cost to Fix: $500 - $3,000+ per component.
  • Recalls: None Found

Electrical

• COMAND System Issues
  • Description/Symptoms: The COMAND infotainment system can experience issues such as freezing, lagging, or complete failure.
  • Solution: Software updates can sometimes resolve the issue. In other cases, the COMAND unit may need to be replaced.
  • Estimated Cost to Fix: $200 (software update) to $2,000+ (unit replacement).
  • Recalls: None Found
• Battery Drain
  • Description/Symptoms: Some owners have reported experiencing excessive battery drain, particularly when the vehicle is not driven regularly. This can lead to difficulty starting the car or a completely dead battery.
  • Solution: Diagnose and repair any parasitic drains in the electrical system. Replace the battery with a new, high-quality unit.
  • Estimated Cost to Fix: $100 (battery replacement) to $500+ (diagnosing and repairing electrical issues).
  • Recalls: None Found

Exterior

• Convertible Top Malfunctions
  • Description/Symptoms: The convertible top mechanism can experience issues such as getting stuck, failing to open or close completely, or making unusual noises during operation.
  • Solution: Diagnose and repair any mechanical issues with the convertible top mechanism. Lubricate moving parts. In some cases, the hydraulic cylinders or pump may need to be replaced.
  • Estimated Cost to Fix: $500 - $3,000+ depending on the complexity of the repair.
  • Recalls: None Found

Interior

• Seat Heater/Cooler Malfunctions
  • Description/Symptoms: The seat heaters and coolers can sometimes fail to function properly.
  • Solution: Diagnose and replace faulty heating/cooling elements or control modules.
  • Estimated Cost to Fix: $300 - $1,000+
  • Recalls: None Found

Summary

The 2016 Mercedes-Benz SL550 offers a luxurious and powerful driving experience, but potential owners should be aware of the common issues that can arise. The air suspension and convertible top mechanisms can be particularly costly to repair. Electrical issues with the COMAND system and battery drain can also be frustrating. While engine and transmission problems are relatively less frequent, they can also be expensive to address. Overall, the SL550 requires careful maintenance and can potentially incur significant repair costs, particularly as it ages.