2020 Mercedes-Benz SLC300

The 2020 Mercedes-Benz SLC300 is a stylish and sporty roadster, offering a blend of luxury and performance. The SLC300 is equipped with a 2.0-liter turbocharged inline-4 engine producing 241 horsepower and 273 lb-ft of torque, paired with a 9G-TRONIC 9-speed automatic transmission. While admired for its retractable hardtop, nimble handling, and upscale interior, some owners have reported certain issues. Dislikes often include the limited rear visibility with the top up, tight cabin space, and the higher price point compared to some competitors. The SLC43 AMG with a 3.0L V6 Biturbo and the SLC Final Edition models were also available but are not covered here.

Engine

2.0L Turbocharged Inline-4

• Oil Leaks from Valve Cover Gasket
  • Description/Symptoms: Oil leaking onto the exhaust manifold, causing a burning smell. Visible oil around the valve cover.
  • Solution: Replacing the valve cover gasket.
  • Estimated Cost to Fix: $200 - $400
  • Recalls: None Found
• Faulty Camshaft Position Sensor
  • Description/Symptoms: Engine misfires, rough idling, check engine light illuminated. Diagnostic codes pointing to the camshaft position sensor.
  • Solution: Replacing the faulty camshaft position sensor.
  • Estimated Cost to Fix: $150 - $300
  • Recalls: None Found

Transmission

9G-TRONIC 9-Speed Automatic

• Rough Shifting
  • Description/Symptoms: Harsh or jerky shifting between gears, especially at lower speeds. Hesitation or delay during gear changes.
  • Solution: Performing a transmission fluid flush and software update. If the problem persists, valve body replacement may be necessary.
  • Estimated Cost to Fix: $300 (flush and update) - $1500+ (valve body)
  • Recalls: None Found
• Torque Converter Issues
  • Description/Symptoms: Shuddering or vibration at low speeds, especially when accelerating from a stop.
  • Solution: Torque converter replacement.
  • Estimated Cost to Fix: $1800 - $3000+
  • Recalls: None Found

Suspension

• No Issues Found

Electrical

• Malfunctioning Retractable Hardtop
  • Description/Symptoms: The roof gets stuck either while opening or closing, or takes longer than normal. Error message on the dashboard display.
  • Solution: Diagnosing the hydraulic pump, sensors, or wiring harness. Repairing or replacing the faulty component.
  • Estimated Cost to Fix: $300 - $2000+, depending on the component needing replacement.
  • Recalls: None Found
• COMAND System Freezing/Crashing
  • Description/Symptoms: The infotainment screen freezes, becomes unresponsive, or restarts unexpectedly. Loss of functionality for navigation, audio, and other features.
  • Solution: Performing a software update. If the problem persists, replacing the COMAND unit may be necessary.
  • Estimated Cost to Fix: $100 (software update) - $1500+ (COMAND unit replacement).
  • Recalls: None Found

Exterior

• No Issues Found

Interior

• Seat Heater Failure
  • Description/Symptoms: The seat heaters do not function, or only heat intermittently.
  • Solution: Replacing the seat heating element or control module.
  • Estimated Cost to Fix: $200 - $800+
  • Recalls: None Found

Summary

The 2020 Mercedes-Benz SLC300, while generally reliable, can experience issues with the engine (oil leaks, sensor failures) and transmission (rough shifting, torque converter problems). The electrical system, particularly the retractable hardtop and COMAND system, is another area of concern. These issues can range from minor inconveniences to more costly repairs. Severity varies depending on the specific issue, but the potential costs of repairs, particularly for the transmission and retractable hardtop mechanisms, should be considered.