2009 Mercedes-Benz GL320

The 2009 Mercedes-Benz GL320 is a full-size luxury SUV known for its spaciousness and comfortable ride. The GL320 specifically features a 3.0-liter turbodiesel V6 engine producing 215 horsepower and 398 lb-ft of torque. Other engine options for the 2009 GL-Class included the GL450 with a 4.7-liter V8 and the GL550 with a 5.5-liter V8. All engine options were paired with a 7-speed automatic transmission (7G-Tronic). Owners generally appreciate the GL320’s towing capacity, luxurious interior, and smooth ride. Common complaints include higher maintenance costs associated with the diesel engine and potential reliability issues with the air suspension.

Engine

3.0L Turbodiesel V6 (OM642)

• Oil Cooler Seal Leaks
  • Description/Symptoms: Oil leaks from the oil cooler seals, often noticed as oil drips under the vehicle or a burning oil smell. This can lead to low oil levels and potential engine damage if not addressed.
  • Solution: Replace the oil cooler seals.
  • Estimated Cost to Fix: $400 - $800+
  • Recalls: None Found
• Swirl Flap Motor Failure
  • Description/Symptoms: Check engine light illuminated, potential for reduced engine performance, and possible limp mode. Diagnostic codes often point to the swirl flap motor or related components.
  • Solution: Replacement of the swirl flap motor or complete intake manifold replacement is required.
  • Estimated Cost to Fix: $500 - $1500+
  • Recalls: None Found
• Diesel Particulate Filter (DPF) Issues
  • Description/Symptoms: Reduced engine performance, warning lights related to the DPF, and potential for the vehicle to enter limp mode. This can be caused by soot buildup or a faulty DPF sensor.
  • Solution: DPF regeneration (either forced or through driving), sensor replacement, or DPF replacement.
  • Estimated Cost to Fix: $300 - $2000+
  • Recalls: None Found

Transmission

7-Speed Automatic (7G-Tronic - 722.9)

• Conductor Plate Failure
  • Description/Symptoms: Erratic shifting, transmission slipping, getting stuck in one gear, or complete loss of gear engagement.
  • Solution: Replacement of the conductor plate and adaptation of the TCU.
  • Estimated Cost to Fix: $800 - $1500+
  • Recalls: None Found
• Torque Converter Issues
  • Description/Symptoms: Shuddering or vibration, especially at lower speeds, can indicate issues with the torque converter.
  • Solution: Torque converter replacement.
  • Estimated Cost to Fix: $1200 - $2500+
  • Recalls: None Found

Suspension

• Air Suspension Failure
  • Description/Symptoms: Vehicle sagging on one or more corners, failure to maintain proper ride height, “Ride Height Malfunction” warning light. This is often caused by leaking air struts or a failing air compressor.
  • Solution: Replacement of faulty air struts, air compressor, or valve block.
  • Estimated Cost to Fix: $800 - $2000+ per strut, $500 - $1000+ for the compressor.
  • Recalls: None Found

Electrical

• Glow Plug Module Failure
  • Description/Symptoms: Difficulty starting in cold weather, check engine light, and codes related to glow plug function.
  • Solution: Replacement of the glow plug module and/or individual glow plugs.
  • Estimated Cost to Fix: $200 - $600+
  • Recalls: None Found
• Battery Drain Issues
  • Description/Symptoms: The vehicle’s battery drains quickly, especially when the car is not being used. This can be due to a faulty component not shutting down properly or parasitic draw.
  • Solution: Diagnose and repair the source of the parasitic draw. This can involve replacing a faulty module or repairing wiring issues.
  • Estimated Cost to Fix: $100 - $500+ (Diagnosis and repair)
  • Recalls: None Found

Exterior

• Sunroof Issues
  • Description/Symptoms: Sunroof becoming stuck, failing to open or close properly, or leaking.
  • Solution: Repair or replacement of sunroof motor, rails, or seals.
  • Estimated Cost to Fix: $300 - $1000+
  • Recalls: None Found

Interior

• Navigation/COMAND System Issues
  • Description/Symptoms: The COMAND system may freeze, fail to boot, or display error messages. The navigation system may lose its GPS signal.
  • Solution: Software update or replacement of the COMAND unit.
  • Estimated Cost to Fix: $200 - $1500+
  • Recalls: None Found

Summary

The 2009 Mercedes-Benz GL320, while a luxurious and capable SUV, has several potential issues that owners should be aware of. The diesel engine can be prone to oil leaks and DPF problems, while the air suspension and 7G-Tronic transmission can also experience failures. Electrical issues, such as glow plug module failures and battery drain, can also occur. Repair costs can range from a few hundred dollars to several thousand depending on the severity of the issue, making it essential to have a thorough inspection performed before purchasing a used GL320.