2018 Mercedes-Benz C43 AMG

The 2018 Mercedes-Benz C43 AMG is a performance-oriented version of the C-Class sedan, coupe, and convertible. It boasts a turbocharged 3.0-liter V6 engine producing 362 horsepower and 384 lb-ft of torque, paired with a 9G-TRONIC nine-speed automatic transmission and 4MATIC all-wheel drive. While owners generally appreciate the C43’s blend of performance, luxury, and technology, some common complaints include issues with the infotainment system, suspension, and certain engine components. Other engine options are not available in the C43 AMG. The C300 has a 2.0L turbocharged inline 4 with 241 hp and 273 lb-ft. The C63 AMG has a 4.0L biturbo V8 with 469 hp and 479 lb-ft, or 503 hp and 516 lb-ft in the C63S.

Engine

3.0L Turbocharged V6

• Turbocharger Failure
  • Description/Symptoms: Whining noise from the turbochargers, loss of power, check engine light. Could be a leak in the charge pipes or damaged turbocharger.
  • Solution: Replacement of the turbocharger(s) and/or charge pipes.
  • Estimated Cost to Fix: $2,000 - $4,000+ (depending on location, parts availability, and if one or both turbos need replacement).
  • Recalls: None Found
• Coolant Leaks
  • Description/Symptoms: Coolant level dropping, overheating, visible coolant leaks around the engine.
  • Solution: Identify and replace the leaking component (water pump, hoses, thermostat housing, etc.).
  • Estimated Cost to Fix: $200 - $1,500+ depending on the source of the leak and extent of repairs.
  • Recalls: None Found

Transmission

9G-TRONIC 9-Speed Automatic (725.0)

• Harsh Shifting/Hesitation
  • Description/Symptoms: Jerky or abrupt gear changes, hesitation when accelerating, particularly at lower speeds, transmission slipping.
  • Solution: Transmission fluid flush and adaptation reset. In some cases, valve body replacement or full transmission replacement might be required if the issue persists.
  • Estimated Cost to Fix: $300 - $8,000+ depending on the severity and necessary repairs.
  • Recalls: None Found
• Torque Converter Issues
  • Description/Symptoms: Shuddering at low RPMs. Can cause abnormal vibration and shifting issues.
  • Solution: Replacement of the torque converter.
  • Estimated Cost to Fix: $1,500 - $3,000+ depending on labor and parts.
  • Recalls: None Found

Suspension

• Air Suspension Malfunctions (if equipped)
  • Description/Symptoms: Vehicle sitting unevenly, ride height not adjusting properly, warning lights on the dashboard.
  • Solution: Diagnose and replace the faulty component (air struts, air compressor, ride height sensors).
  • Estimated Cost to Fix: $800 - $3,000+ per strut (depending on location and parts). Compressor replacement can be $500 - $1,500.
  • Recalls: None Found
• Damper Issues (Adaptive Dampers)
  • Description/Symptoms: Clunking or knocking sounds when going over bumps, poor ride quality, vehicle bouncing excessively.
  • Solution: Replacement of the faulty damper.
  • Estimated Cost to Fix: $500 - $2,000+ per damper (depending on location and parts).
  • Recalls: None Found

Electrical

• Infotainment System Freezing/Crashing
  • Description/Symptoms: The COMAND system freezes, reboots unexpectedly, or becomes unresponsive.
  • Solution: Software update, reset the system, or, in some cases, replacement of the COMAND unit.
  • Estimated Cost to Fix: $0 (software updates) - $2,000+ (COMAND unit replacement).
  • Recalls: None Found
• Sensor Malfunctions
  • Description/Symptoms: Various warning lights on the dashboard related to driver-assistance systems (blind-spot monitoring, lane keeping assist, parking sensors).
  • Solution: Diagnose and replace the faulty sensor(s).
  • Estimated Cost to Fix: $200 - $800+ per sensor, depending on the sensor location and type.
  • Recalls: None Found
• Battery Drain
  • Description/Symptoms: Car failing to start, needing to be jump-started, frequent dead battery.
  • Solution: Test battery and charging system. If good, perform a parasitic draw test to identify the circuit causing the battery drain and repair the faulty component.
  • Estimated Cost to Fix: $150 - $500+ depending on the complexity of the repair.
  • Recalls: None Found

Exterior

• No Issues Found

Interior

• Sunroof Issues
  • Description/Symptoms: Sunroof not opening or closing properly, getting stuck, making excessive noise.
  • Solution: Cleaning and lubricating the tracks, repairing or replacing damaged components (motor, cables, etc.).
  • Estimated Cost to Fix: $200 - $1,000+.
  • Recalls: None Found
• Seat Motor Failure
  • Description/Symptoms: Seat not moving or adjusting correctly in one or more directions.
  • Solution: Replace the seat motor.
  • Estimated Cost to Fix: $300 - $800+ depending on the specific motor and labor.
  • Recalls: None Found

Summary

The 2018 Mercedes-Benz C43 AMG is generally a reliable vehicle, but some owners have reported issues with the engine, transmission, suspension, and electrical systems. Turbocharger failures and harsh shifting are among the most concerning and potentially costly problems. Infotainment system glitches and sensor malfunctions are also common annoyances. While some fixes are relatively inexpensive, others can be costly, particularly those involving turbocharger, transmission, or air suspension repairs.