2018 Mercedes-Benz SL450

The 2018 Mercedes-Benz SL450 is a luxurious roadster known for its elegant design, comfortable ride, and retractable hardtop. The SL450 is powered by a 3.0-liter twin-turbo V6 engine producing 362 horsepower and 369 lb-ft of torque, paired with a 9G-TRONIC 9-speed automatic transmission. While owners generally appreciate the SL450’s refined performance and premium features, some common complaints include issues with the electronics, specifically the infotainment system, and occasional problems with the convertible top mechanism. The SL550 model features a more powerful 4.7-liter twin-turbo V8 engine.

Engine

3.0L Twin-Turbo V6

• Oil Leaks
  • Description/Symptoms: Oil leaks can occur from various locations, including the valve cover gaskets and the oil filter housing. Symptoms include visible oil drips under the car, a burning oil smell, and low oil levels.
  • Solution: Replacing the leaking gasket or seal. In some cases, the entire oil filter housing may need replacement.
  • Estimated Cost to Fix: $200 - $1000+ (depending on the source and severity of the leak)
  • Recalls: None Found

Electrical

• Infotainment System Malfunctions
  • Description/Symptoms: The COMAND infotainment system can experience glitches, freezing, screen blackouts, and navigation errors.
  • Solution: Software updates, system resets, or replacement of the COMAND unit.
  • Estimated Cost to Fix: $100 - $1500+ (depending on severity and dealer labor)
  • Recalls: None Found
• Battery Drain
  • Description/Symptoms: Excessive battery drain can lead to difficulty starting the car, especially after periods of inactivity.
  • Solution: Identifying and addressing the parasitic draw. This may involve replacing a faulty module or repairing wiring issues.
  • Estimated Cost to Fix: $150 - $500+ (depending on the source of the draw)
  • Recalls: None Found
• Convertible Top Issues
  • Description/Symptoms: The convertible top may fail to operate correctly, get stuck, or display error messages. This could be due to hydraulic pump failure, sensor malfunctions, or wiring problems.
  • Solution: Diagnosing the specific issue and replacing the faulty components.
  • Estimated Cost to Fix: $500 - $3000+ (depending on the complexity of the repair)
  • Recalls: None Found

Suspension

• Air Suspension Problems (if equipped)
  • Description/Symptoms: If equipped with air suspension, issues such as air leaks, compressor failure, and sagging can occur.
  • Solution: Replacing leaking air struts, the air compressor, or associated components.
  • Estimated Cost to Fix: $800 - $3000+ (depending on the component needing replacement)
  • Recalls: None Found

Interior

• Seat Motor Malfunctions
  • Description/Symptoms: Power seats may become inoperable or move erratically due to faulty motors or switches.
  • Solution: Replacing the affected seat motor or switch.
  • Estimated Cost to Fix: $300 - $800+ (depending on part and labor)
  • Recalls: None Found

Exterior

• Convertible Top Seal Leaks
  • Description/Symptoms: Water leaks around the convertible top seals, particularly in heavy rain or car washes.
  • Solution: Replacing or adjusting the seals.
  • Estimated Cost to Fix: $200 - $800+ (depending on the extent of the leaks)
  • Recalls: None Found

Summary

The 2018 Mercedes-Benz SL450 generally offers a luxurious and enjoyable driving experience. However, potential buyers should be aware of the common issues, particularly those related to the electrical system and convertible top mechanism. While some issues are relatively minor and inexpensive to fix, others, such as air suspension problems or major infotainment malfunctions, can be more costly. Inspecting the vehicle thoroughly and obtaining a pre-purchase inspection from a qualified mechanic is recommended to identify any potential issues before making a purchase.