2009 Mercedes-Benz ML550

The 2009 Mercedes-Benz ML550 is a mid-size luxury SUV that offers a blend of performance and comfort. The ML550 came standard with a 5.5L V8 engine that produced 382 horsepower and 391 lb-ft of torque. Other engine options for the 2009 ML-Class included a 3.5L V6 (ML350) and a 3.0L turbodiesel V6 (ML320 BlueTec). All engines were paired with a 7-speed automatic transmission. Owners often praise the ML550 for its powerful engine, luxurious interior, and comfortable ride. Common complaints revolve around its high maintenance costs, potential electrical issues, and fuel economy.

Engine

5.5L V8

• Camshaft Adjuster Solenoid Failure
  • Description/Symptoms: The engine may experience rough idling, reduced power, and a check engine light. Diagnostic codes often indicate issues with the camshaft position.
  • Solution: Replacement of the faulty camshaft adjuster solenoid(s).
  • Estimated Cost to Fix: $200 - $500+
  • Recalls: None Found
• Oil Leaks (Valve Cover Gaskets, Oil Filter Housing)
  • Description/Symptoms: Visible oil leaks around the valve covers or oil filter housing. Burning oil smell may be present. Low oil levels may be observed.
  • Solution: Replacement of the valve cover gaskets and/or oil filter housing gasket.
  • Estimated Cost to Fix: $300 - $800+ (depending on location and extent of the leak)
  • Recalls: None Found

Transmission

7-Speed Automatic (7G-Tronic)

• Torque Converter Failure
  • Description/Symptoms: Shuddering during gear changes, especially at lower speeds. May also experience a delayed or harsh engagement of gears.
  • Solution: Replacement of the torque converter. Transmission flush and filter change may also be recommended.
  • Estimated Cost to Fix: $1,500 - $3,000+
  • Recalls: None Found
• Valve Body Issues
  • Description/Symptoms: Erratic shifting, harsh shifting, or failure to shift properly. The transmission may get stuck in a gear.
  • Solution: Replacement or rebuild of the valve body.
  • Estimated Cost to Fix: $800 - $2,000+
  • Recalls: None Found

Suspension

• Airmatic Suspension Failure
  • Description/Symptoms: Vehicle sagging or sitting unevenly. Compressor may run constantly. Warning messages on the dashboard related to the air suspension system.
  • Solution: Replacement of the air struts/springs, air compressor, or valve block. Diagnosing and repairing air leaks in the system is also crucial.
  • Estimated Cost to Fix: $800 - $2,000+ per strut/spring; $500 - $1,500+ for compressor; $300-$800+ for valve block.
  • Recalls: None Found

Electrical

• EIS (Electronic Ignition Switch) Failure
  • Description/Symptoms: Difficulty starting the vehicle or inability to start at all. Key may not be recognized by the ignition system.
  • Solution: Replacement of the EIS module and potentially reprogramming.
  • Estimated Cost to Fix: $800 - $1,500+
  • Recalls: None Found
• SAM (Signal Acquisition Module) Issues
  • Description/Symptoms: Various electrical malfunctions, such as malfunctioning lights, wipers, or power windows. Diagnostic codes may point to a faulty SAM unit.
  • Solution: Replacement of the faulty SAM unit and reprogramming.
  • Estimated Cost to Fix: $500 - $1,200+
  • Recalls: None Found

Exterior

• Rust (Specific Areas)
  • Description/Symptoms: Rust formation around the wheel wells, door edges, and underbody.
  • Solution: Rust repair, body panel replacement, and repainting.
  • Estimated Cost to Fix: $300 - $2,000+ (depending on the severity and location of the rust)
  • Recalls: None Found

Interior

• Sunroof Issues
  • Description/Symptoms: Sunroof may be stuck open or closed. Motor may be noisy or fail to operate.
  • Solution: Repair or replacement of the sunroof motor, rails, or other components.
  • Estimated Cost to Fix: $300 - $1,000+
  • Recalls: None Found

Summary: The 2009 Mercedes-Benz ML550, while offering luxury and performance, can be prone to several issues. The most concerning are related to the air suspension and the electrical system, which can be costly to repair. Engine and transmission issues, such as oil leaks and torque converter problems, can also arise. While not every ML550 will experience all of these issues, it’s crucial to be aware of them when considering purchasing this vehicle. Expect repairs to be on the higher side due to the cost of parts and the complexity of the vehicle’s systems.