2012 Mercedes-Benz GL550

The 2012 Mercedes-Benz GL550 is a full-size luxury SUV known for its powerful engine, spacious interior, and comfortable ride. The GL-Class offered two engine options for the 2012 model year: a 4.6L V8 and a 5.5L V8 (GL550). The GL550’s 5.5L V8 engine produces 429 horsepower and 516 lb-ft of torque. Owners generally appreciate the vehicle’s luxurious features, smooth ride, and powerful engine. Common complaints often include high maintenance costs, complex electronics that can be prone to failure, and the vehicle’s large size making it difficult to maneuver in tight spaces.

Engine

5.5L V8 (GL550)

• Oil Leaks from Valve Cover Gaskets
  • Description/Symptoms: Oil leaks are a common issue on the 5.5L V8. Oil may be visible around the valve covers or on the engine block. Burning smell may be present.
  • Solution: Replacement of the valve cover gaskets.
  • Estimated Cost to Fix: $500 - $1000+
• Check Engine Light due to Camshaft Adjuster Solenoid Failure
  • Description/Symptoms: Check engine light, rough idling, loss of power. Diagnostic codes may indicate issues with the camshaft position or timing.
  • Solution: Replacement of the faulty camshaft adjuster solenoid(s).
  • Estimated Cost to Fix: $300 - $700+
• Fuel Injector Failure
  • Description/Symptoms: Rough idle, misfires, poor fuel economy, and a check engine light.
  • Solution: Replacement of the faulty fuel injector(s).
  • Estimated Cost to Fix: $300 - $800+
• Engine Mount Failure
  • Description/Symptoms: Excessive engine vibration, clunking noises during acceleration or deceleration.
  • Solution: Replacement of the engine mounts.
  • Estimated Cost to Fix: $600 - $1200+

Recalls: None Found

Transmission

7G-TRONIC (722.9) 7-Speed Automatic Transmission (Both Engine Options)

• Torque Converter Issues
  • Description/Symptoms: Shuddering or vibration during gear changes, especially at lower speeds. Hesitation when accelerating.
  • Solution: Torque converter replacement.
  • Estimated Cost to Fix: $2500 - $4000+
• Conductor Plate Failure
  • Description/Symptoms: Erratic shifting, getting stuck in gear, or complete transmission failure. Check engine light may be illuminated.
  • Solution: Replacement of the conductor plate.
  • Estimated Cost to Fix: $800 - $1500+
• Valve Body Issues
  • Description/Symptoms: Hard or delayed shifts, slipping between gears.
  • Solution: Valve body replacement or rebuild.
  • Estimated Cost to Fix: $1500 - $3000+ Recalls: None Found

Suspension

• Airmatic Suspension Failure
  • Description/Symptoms: Vehicle sagging on one or more corners, the compressor running constantly, ride height not adjusting properly, or “Visit Workshop” message on the dashboard.
  • Solution: Replacement of the air struts, air compressor, or valve block.
  • Estimated Cost to Fix: $1000 - $2500+ per air strut, $800 - $1500+ for the compressor, $300 - $700+ for the valve block.
• Air Suspension Compressor Failure
  • Description/Symptoms: The vehicle will not raise to the proper ride height, or takes an extremely long time to do so. Error message regarding Airmatic system.
  • Solution: Replace air suspension compressor.
  • Estimated Cost to Fix: $800 - $1500+
• Air Strut Leaks
  • Description/Symptoms: Car is sagging and deflating. The Airmatic compressor is running longer than normal.
  • Solution: Replacing the leaking struts with new ones.
  • Estimated Cost to Fix: $1000 - $2500+ per air strut

Recalls: None Found

Electrical

• Battery Drain Issues
  • Description/Symptoms: Vehicle battery drains quickly, especially when the vehicle is not in use for extended periods.
  • Solution: Diagnosing and repairing parasitic drain. Potential replacement of the battery, alternator, or other electrical components.
  • Estimated Cost to Fix: $150 - $1000+
• SAM (Signal Acquisition Module) Failure
  • Description/Symptoms: Multiple electrical issues, such as lights not working, wipers malfunctioning, or other electronic systems failing.
  • Solution: Replacement or reprogramming of the SAM unit.
  • Estimated Cost to Fix: $800 - $1500+
• Navigation/Entertainment System Issues
  • Description/Symptoms: Screen freezes, system reboots, no audio, or difficulty connecting to Bluetooth.
  • Solution: Software update, replacement of the head unit, or repair of the wiring harness.
  • Estimated Cost to Fix: $200 - $1500+

Recalls: None Found

Exterior

• Sunroof Issues
  • Description/Symptoms: Sunroof not opening or closing properly, making excessive noise, or leaking water.
  • Solution: Repair or replacement of the sunroof motor, tracks, or seals.
  • Estimated Cost to Fix: $300 - $1200+

Recalls: None Found

Interior

• Seat Heater Malfunction
  • Description/Symptoms: Seat heaters not working or overheating.
  • Solution: Replacement of the heating element or control module.
  • Estimated Cost to Fix: $300 - $800+ per seat
• Power Seat Motor Failure
  • Description/Symptoms: Seat is not adjusting properly, may be stuck in one position.
  • Solution: Replacement of the power seat motor.
  • Estimated Cost to Fix: $400 - $1000+ per seat

Recalls: None Found

Summary

The 2012 Mercedes-Benz GL550, while a luxurious and capable SUV, has some common issues. Engine oil leaks, Airmatic suspension problems, and electrical issues like battery drain are prevalent. Transmission issues can also occur. The severity ranges from minor inconveniences to major repairs, with costs potentially reaching several thousand dollars for suspension or transmission work. Prospective buyers should be aware of these potential issues and factor them into their purchasing decision, as well as budgeting for ongoing maintenance.