2018 Mercedes-Benz GLS63 AMG

The 2018 Mercedes-Benz GLS63 AMG is a high-performance SUV that blends luxury with potent power. Its main powerplant is a handcrafted 5.5-liter biturbo V8 engine, producing 577 horsepower and 561 lb-ft of torque. The GLS63 AMG is known for its brisk acceleration, comfortable ride (despite its sporty tuning), and luxurious interior appointments. However, some owners have voiced concerns over maintenance costs, fuel economy, and the complexity of its electronic systems. Other GLS models offered different engines, including the GLS450 with a 3.0-liter V6, and the GLS550 with a 4.7-liter V8. All GLS models in 2018 were equipped with a 9-speed automatic transmission.

Engine

5.5L Biturbo V8

• Oil Leaks
  • Description/Symptoms: Oil leaks from various engine seals and gaskets, most commonly from the valve cover gaskets, oil filter housing gasket, and rear main seal. Symptoms include visible oil drips under the vehicle, burning oil smell, and low oil levels.
  • Solution: Replace the leaking gasket or seal.
  • Estimated Cost to Fix: $200 - $1,500+, depending on the location and severity of the leak.
  • Recalls: None Found
• Turbocharger Issues
  • Description/Symptoms: Whining noise from the turbocharger, loss of power, and potentially turbocharger failure.
  • Solution: Replacing the turbocharger(s).
  • Estimated Cost to Fix: $3,000 - $6,000+
  • Recalls: None Found

Transmission

9-Speed Automatic Transmission (9G-Tronic)

• Rough Shifting/Hesitation
  • Description/Symptoms: Harsh or delayed shifts, particularly between lower gears. Hesitation upon acceleration.
  • Solution: Software update/reprogramming of the transmission control module (TCM). In some cases, valve body replacement is necessary.
  • Estimated Cost to Fix: $200 - $4,000+ depending on if it needs to be reprogrammed or valve body replacement
  • Recalls: None Found

Suspension

• Air Suspension Failure
  • Description/Symptoms: The vehicle sits unevenly, or the suspension fails to raise or lower properly. Airmatic warning lights on the dashboard.
  • Solution: Replace the failed air strut(s), air compressor, or air lines.
  • Estimated Cost to Fix: $1,000 - $3,000+ per strut or component.
  • Recalls: None Found

Electrical

• Malfunctioning Sensors
  • Description/Symptoms: Various warning lights on the dashboard related to systems such as ABS, ESP, or tire pressure monitoring.
  • Solution: Diagnose and replace the faulty sensor.
  • Estimated Cost to Fix: $100 - $500+ per sensor depending on the location.
  • Recalls: None Found
• COMAND System Issues
  • Description/Symptoms: Freezing, glitching, or unresponsive infotainment system.
  • Solution: Software update. In some cases, replacement of the COMAND unit.
  • Estimated Cost to Fix: $100-$2,000+ depending on software and parts
  • Recalls: None Found

Exterior

• Automatic Tailgate Malfunction
  • Description/Symptoms: Tailgate not opening/closing. Binding on the opening/closing mechanism.
  • Solution: Tailgate motor/actuator or the strut replacement.
  • Estimated Cost to Fix: $300-$1,000+
  • Recalls: None Found

Interior

• Seat Adjustment Issues
  • Description/Symptoms: Power seats not adjusting properly, or motors making grinding noises.
  • Solution: Replace the faulty seat motor or associated components.
  • Estimated Cost to Fix: $200 - $800+ per seat
  • Recalls: None Found

Summary

The 2018 Mercedes-Benz GLS63 AMG offers impressive performance and luxury, but it is not without its potential issues. The most common complaints revolve around oil leaks in the engine, rough shifting from the transmission, air suspension problems, and electrical glitches. While some issues can be resolved with relatively inexpensive fixes, others, such as turbocharger or air suspension component replacement, can be quite costly. Owners should be prepared for potentially higher maintenance costs associated with this high-performance SUV.