2008 Mercedes-Benz R320

The 2008 Mercedes-Benz R320 is a luxury wagon known for its spacious interior and comfortable ride. The R320 was offered with a 3.0L diesel V6 engine that produced 215 horsepower and 398 lb-ft of torque. Other engine options included a 3.5L gasoline V6 and a 5.5L V8. The R320 is generally liked for its versatility and luxury features, but disliked for its potential for high maintenance costs, especially with the diesel engine.

Engine

3.0L Diesel V6 (OM642)

• Oil Cooler Seal Leaks
  • Description/Symptoms: Oil leaks are common around the oil cooler seals. The oil may leak onto other engine components and cause a burning smell. Visible oil drips may also be present.
  • Solution: Replace the oil cooler seals.
  • Estimated Cost to Fix: $300 - $600+
  • Recalls: None Found
• Swirl Motor Failure
  • Description/Symptoms: The swirl motor controls the intake manifold flaps which optimizes air flow at lower RPMs. Failure of the swirl motor will often trigger a check engine light.
  • Solution: Replace the swirl motor. Some owners opt to delete the swirl flaps altogether to prevent future issues.
  • Estimated Cost to Fix: $500 - $1000+
  • Recalls: None Found
• Diesel Particulate Filter (DPF) Issues
  • Description/Symptoms: The DPF can become clogged, especially with short trip driving. This can lead to reduced engine performance and a check engine light.
  • Solution: Attempt to regenerate the DPF through a forced regeneration or extended highway driving. If regeneration fails, the DPF may need to be replaced.
  • Estimated Cost to Fix: $500 - $2000+
  • Recalls: None Found
• EGR Valve Issues
  • Description/Symptoms: The EGR valve can become clogged with carbon deposits, leading to poor engine performance, rough idling, and a check engine light.
  • Solution: Clean or replace the EGR valve.
  • Estimated Cost to Fix: $300 - $700+
  • Recalls: None Found

Transmission

7G-Tronic (722.9)

• Valve Body Issues
  • Description/Symptoms: The 7G-Tronic transmission is known to have issues with the valve body. Symptoms can include harsh shifting, slipping, and delayed engagement.
  • Solution: Replace or rebuild the valve body. Some owners also opt to replace the conductor plate at the same time.
  • Estimated Cost to Fix: $1000 - $3000+
  • Recalls: None Found
• Torque Converter Failure
  • Description/Symptoms: The torque converter may fail, leading to shuddering, vibrations, and difficulty shifting.
  • Solution: Replace the torque converter.
  • Estimated Cost to Fix: $800 - $2000+
  • Recalls: None Found

Suspension

• Airmatic Suspension Leaks/Failure
  • Description/Symptoms: The Airmatic air suspension system is prone to leaks and compressor failure, resulting in a sagging vehicle, especially overnight. A “Vehicle Level Too Low” warning may also appear.
  • Solution: Replace the leaking air springs, air compressor, or both. It is recommended to replace air springs in pairs.
  • Estimated Cost to Fix: $800 - $2000+ per air spring, $500 - $1500+ for the compressor.
  • Recalls: None Found

Electrical

• SAM (Signal Acquisition Module) Failure
  • Description/Symptoms: The SAM module controls various electrical functions. Failure can cause a wide range of issues, including lighting problems, issues with the wipers, and problems with the central locking system.
  • Solution: Replace the faulty SAM module and have it properly programmed to the vehicle.
  • Estimated Cost to Fix: $800 - $2000+
  • Recalls: None Found
• EIS (Electronic Ignition Switch) Failure
  • Description/Symptoms: The EIS can fail, preventing the car from starting.
  • Solution: Replace the EIS and have it programmed to the vehicle.
  • Estimated Cost to Fix: $800 - $1800+
  • Recalls: None Found

Exterior

• Rust Issues
  • Description/Symptoms: Rust can occur, especially in areas with harsh weather conditions.
  • Solution: Repair and repaint affected areas.
  • Estimated Cost to Fix: Varies greatly depending on the extent of the rust.
  • Recalls: None Found

Interior

• Sunroof Issues
  • Description/Symptoms: The sunroof motor may fail, preventing the sunroof from opening or closing properly. The sunroof track can also become damaged.
  • Solution: Replace the sunroof motor or repair/replace the sunroof track.
  • Estimated Cost to Fix: $300 - $1000+
  • Recalls: None Found

Summary

The 2008 Mercedes-Benz R320 can be a comfortable and versatile vehicle, but it is prone to several potentially expensive issues. The diesel engine is known for oil leaks, swirl motor failures, and DPF problems. The 7G-Tronic transmission can suffer from valve body and torque converter failures. The Airmatic suspension is also a common source of problems. Electrical issues with the SAM module and EIS are also possible. Overall, potential owners should be aware of these potential issues and factor them into their purchasing decision, as repair costs can be significant.