2009 Mercedes-Benz R320

The 2009 Mercedes-Benz R320 is a luxury SUV known for its spacious interior and comfortable ride. The R320 was offered with a diesel engine that provided a good balance of fuel economy and performance. The R320 offered seating for up to seven passengers, making it a practical choice for families. Some owners appreciate the car’s refined driving experience, while others find the maintenance costs to be high and the styling to be somewhat bland. The 2009 R320 was available with a 3.0L V6 diesel engine rated at 215 hp and 398 lb-ft of torque. All engine options were paired with a 7G-TRONIC 7-speed automatic transmission.

Engine

3.0L Diesel V6

• Oil Cooler Seal Leaks
  • Description/Symptoms: Oil leaks are observed near the oil cooler, often dripping onto other engine components. This can lead to a burning oil smell.
  • Solution: Replace the oil cooler seals.
  • Estimated Cost to Fix: $400 - $700+
  • Recalls: None Found
• Glow Plug Failure
  • Description/Symptoms: Difficulty starting in cold weather, engine misfires, and a check engine light illuminating. Diagnostic codes related to glow plug malfunctions will be present.
  • Solution: Replace the faulty glow plug(s).
  • Estimated Cost to Fix: $200 - $400+
  • Recalls: None Found
• Intake Manifold Swirl Flap Motor Failure
  • Description/Symptoms: Reduced engine performance, poor fuel economy, and a check engine light with diagnostic codes related to the swirl flap system.
  • Solution: Replacing the intake manifold with an updated design that addresses the swirl flap issue.
  • Estimated Cost to Fix: $1,200 - $2,000+
  • Recalls: None Found

Transmission

7G-TRONIC 7-Speed Automatic

• Torque Converter Failure
  • Description/Symptoms: Shuddering or vibration at low speeds, especially during acceleration. Delayed or harsh shifting.
  • Solution: Replace the torque converter.
  • Estimated Cost to Fix: $1,500 - $3,000+
  • Recalls: None Found
• Conductor Plate Failure
  • Description/Symptoms: Erratic shifting, getting stuck in a gear, or failure to shift at all. The vehicle may go into limp mode. Diagnostic codes related to the transmission control unit (TCU) will be present.
  • Solution: Replace the conductor plate.
  • Estimated Cost to Fix: $800 - $1,500+
  • Recalls: None Found

Suspension

• Air Suspension Compressor Failure
  • Description/Symptoms: The vehicle sits lower than normal, especially at one corner. The air suspension warning light illuminates. The compressor may be noisy or not run at all.
  • Solution: Replace the air suspension compressor. Also inspect the system for leaks.
  • Estimated Cost to Fix: $800 - $1,500+
  • Recalls: None Found
• Air Strut Leaks
  • Description/Symptoms: The vehicle sags or leans to one side, especially after being parked for a while. Hissing sounds may be heard from the air struts.
  • Solution: Replace the leaking air strut(s).
  • Estimated Cost to Fix: $1,000 - $2,000+ per strut
  • Recalls: None Found

Electrical

• EIS (Electronic Ignition Switch) Failure
  • Description/Symptoms: The key may not turn in the ignition, or the vehicle may not start even when the key is recognized.
  • Solution: Replace the EIS. This often requires programming by a Mercedes-Benz dealer or specialist.
  • Estimated Cost to Fix: $800 - $1,500+
  • Recalls: None Found
• SAM (Signal Acquisition Module) Failure
  • Description/Symptoms: Malfunctions in various electrical components, such as lights, wipers, power windows, or door locks. These malfunctions may be intermittent.
  • Solution: Replace the faulty SAM unit. This requires programming to match the vehicle’s configuration.
  • Estimated Cost to Fix: $600 - $1,200+
  • Recalls: None Found

Exterior

• Rear Tail Light Assembly Corrosion
  • Description/Symptoms: Lights not functioning correctly, water intrusion in the assembly, and visible corrosion on the electrical connections.
  • Solution: Replace the tail light assembly and clean/protect the wiring.
  • Estimated Cost to Fix: $300 - $600+
  • Recalls: None Found

Interior

• Sunroof Issues
  • Description/Symptoms: Sunroof motor failure, sunroof getting stuck, or water leaks.
  • Solution: Repair or replace the sunroof motor and/or components. Address any water leaks by cleaning the drainage channels.
  • Estimated Cost to Fix: $300 - $1,000+ depending on the severity.
  • Recalls: None Found

The 2009 Mercedes-Benz R320 can be a comfortable and practical vehicle, but owners should be aware of potential issues. Many of the problems are related to the diesel engine and the air suspension system, which can be costly to repair. Electrical issues, such as EIS and SAM failures, can also be expensive to address. While some issues are relatively minor, others can be more significant and require extensive repairs. Due to this, it would be important to budget for ongoing maintenance and potential repairs when considering the R320.