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2009 Mercedes-Benz GL550

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By Research the Car 4 min read

The 2009 Mercedes-Benz GL550 is a full-size luxury SUV known for its powerful performance, spacious interior, and refined ride. Alongside the GL550, the 2009 GL-Class also offered the GL320 BlueTEC (diesel), the GL450, and the high-performance GL63 AMG. The GL550 boasts a 5.5-liter V8 engine producing 382 horsepower and 391 lb-ft of torque, paired with a 7-speed automatic transmission (7G-Tronic). Owners appreciate the GL550’s luxurious features, comfortable seating, and strong engine. Criticisms often focus on its high running costs, potential for expensive repairs, and somewhat dated technology compared to newer models.

Engine

5.5L V8 (M273)

  • Camshaft Adjuster Solenoid Failure
    • Description/Symptoms: Check engine light, rough idling, reduced engine performance, and potential stalling. Error codes related to camshaft position.
    • Solution: Replacement of the faulty camshaft adjuster solenoid (also known as a cam magnet).
    • Estimated Cost to Fix: $200 - $500+
    • Recalls: None Found
  • Valve Cover Gasket Leaks
    • Description/Symptoms: Oil leaks around the valve covers, visible oil on the engine, burning oil smell, and potentially low oil levels.
    • Solution: Replacement of the valve cover gaskets.
    • Estimated Cost to Fix: $300 - $800+
    • Recalls: None Found
  • Oil Filter Housing Gasket Leaks
    • Description/Symptoms: Oil leaks around the oil filter housing, often dripping down the engine block. This can lead to low oil levels and potential engine damage if left unaddressed.
    • Solution: Replacement of the oil filter housing gasket.
    • Estimated Cost to Fix: $400 - $1000+
    • Recalls: None Found

Transmission

7G-Tronic (722.9)

  • Conductor Plate Failure
    • Description/Symptoms: Erratic shifting, harsh shifting, transmission slipping, getting stuck in a gear, or complete loss of drive. Check engine light illumination and stored transmission fault codes.
    • Solution: Replacement of the conductor plate inside the transmission.
    • Estimated Cost to Fix: $800 - $1500+
    • Recalls: None Found
  • Torque Converter Issues
    • Description/Symptoms: Shuddering during acceleration, especially at lower speeds. Unusual noises (whining or rumbling) from the transmission area.
    • Solution: Replacement of the torque converter.
    • Estimated Cost to Fix: $1200 - $2500+
    • Recalls: None Found

Suspension

  • Airmatic Suspension Leaks/Failure
    • Description/Symptoms: Vehicle sitting unevenly, sinking overnight, harsh ride, “Visit Workshop” message related to Airmatic system. Can manifest as front or rear suspension problems. Compressor might run excessively or fail due to overwork.
    • Solution: Replacement of leaking air struts, air lines, or the air suspension compressor. Sometimes requires replacing the valve block.
    • Estimated Cost to Fix: $800 - $2000+ per strut; $500 - $1200+ for compressor replacement.
    • Recalls: None Found
  • Airmatic Compressor Relay Failure
    • Description/Symptoms: Airmatic compressor runs continuously, leading to compressor burnout. Related to a faulty relay that sticks in the “on” position.
    • Solution: Replacement of the Airmatic compressor relay.
    • Estimated Cost to Fix: $50 - $150+
    • Recalls: None Found

Electrical

  • Battery Drain Issues
    • Description/Symptoms: Vehicle battery frequently draining, especially after sitting for a few days. Difficulty starting the vehicle.
    • Solution: Diagnose and repair parasitic drains. This often involves testing various modules and components to identify the source of the drain. Potential causes include faulty door lock actuators, seat control modules, or the COMAND system.
    • Estimated Cost to Fix: $100 - $500+ (diagnosis); repair costs vary depending on the source of the drain.
    • Recalls: None Found
  • COMAND System Malfunctions
    • Description/Symptoms: The COMAND (Cockpit Management and Data) system may exhibit various issues, including screen freezing, navigation problems, audio malfunctions, and Bluetooth connectivity issues.
    • Solution: Software updates, component replacement (e.g., the COMAND unit itself).
    • Estimated Cost to Fix: $200 - $1500+
    • Recalls: None Found

Exterior

  • Tail Light Assembly Issues
    • Description/Symptoms: Cracked tail light lens, moisture inside tail light assembly, or bulb failures.
    • Solution: Replacement of the tail light assembly.
    • Estimated Cost to Fix: $200-$500+ per tail light.
    • Recalls: None Found

Interior

  • Sunroof Issues
    • Description/Symptoms: Sunroof not opening or closing properly, getting stuck, or making unusual noises.
    • Solution: Lubrication of tracks, repair or replacement of the sunroof motor or associated components.
    • Estimated Cost to Fix: $100 - $800+
    • Recalls: None Found
  • Seat Motor Failures
    • Description/Symptoms: Seat not adjusting properly, motors making grinding noises, or seat controls not responding.
    • Solution: Replacement of the faulty seat motor or repair of the seat control module.
    • Estimated Cost to Fix: $200 - $800+ per motor.
    • Recalls: None Found

Summary

The 2009 Mercedes-Benz GL550 offers luxury and performance, but it’s crucial to be aware of potential issues, particularly concerning the Airmatic suspension, transmission, and electrical systems. These repairs can be costly, so a thorough pre-purchase inspection by a qualified mechanic familiar with Mercedes-Benz vehicles is highly recommended. While the engine itself is generally reliable, leaks are common. Repair costs range from relatively minor fixes to significant expenses.

Mercedes-Benz, GL550
Mercedes-Benz GL550 2009
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