2009 Mercedes-Benz S500

The 2009 Mercedes-Benz S500 is a luxury sedan known for its comfort, advanced technology, and smooth ride. The S500 came standard with a 5.5-liter V8 engine producing 382 horsepower and 391 lb-ft of torque. Other engine options include the S550 with the same 5.5-liter V8 and the S600 with a 5.5-liter V12. All configurations use a 7-speed automatic transmission. Owners generally praise the S500 for its opulent interior, quiet cabin, and plethora of features. Common dislikes include the high cost of maintenance and repairs, and the complexity of the electronic systems which can lead to reliability concerns.

Engine

5.5L V8

• Oil Leaks
  • Description/Symptoms: Oil leaks are common, often originating from the valve cover gaskets, oil filter housing gasket, or the rear main seal. Symptoms include visible oil drips under the car, a burning oil smell, and low oil levels.
  • Solution: Replacing the leaking gaskets or seals is the standard fix. A thorough inspection should be performed to pinpoint the exact source of the leak.
  • Estimated Cost to Fix: $200 - $1500+ depending on the source and the mechanic’s labor rates.
  • Recalls: None Found
• Camshaft Adjuster Solenoid (Cam Magnet) Leaks
  • Description/Symptoms: These solenoids are responsible for controlling the variable valve timing and are prone to leaking oil. Symptoms include oil leaking down the front of the engine, a burning oil smell, and potential check engine light illumination.
  • Solution: Replacing the leaking camshaft adjuster solenoid(s).
  • Estimated Cost to Fix: $200 - $500
  • Recalls: None Found

Transmission

7-Speed Automatic (7G-Tronic)

• Torque Converter Issues
  • Description/Symptoms: Some owners have reported issues with the torque converter, leading to shuddering, vibrations, or erratic shifting.
  • Solution: Replacement of the torque converter. In some cases, flushing the transmission fluid and replacing the filter might temporarily alleviate the symptoms, but ultimately replacement is often necessary.
  • Estimated Cost to Fix: $1,500 - $3,500
  • Recalls: None Found
• Valve Body Problems
  • Description/Symptoms: The valve body controls the flow of transmission fluid. Malfunctions can cause harsh shifting, slipping, or failure to shift altogether.
  • Solution: Replacement or rebuild of the valve body.
  • Estimated Cost to Fix: $800 - $2,500
  • Recalls: None Found

Suspension

• Airmatic Suspension Failure
  • Description/Symptoms: The Airmatic suspension system, while providing a comfortable ride, is a common source of problems. Symptoms include the car sitting unevenly, a harsh ride, the suspension warning light illuminating, or the car failing to rise.
  • Solution: Diagnosis is key to identifying the faulty component, which could be an air strut, the air compressor, or a leak in the air lines. Replacement of the faulty part(s) is typically required.
  • Estimated Cost to Fix: $800 - $2,000+ per strut, $500 - $1,500 for the compressor.
  • Recalls: None Found

Electrical

• Battery Drain
  • Description/Symptoms: Excessive battery drain can be a frustrating issue. Symptoms include a dead battery, especially after the car has been sitting for a short period.
  • Solution: A parasitic draw test is needed to identify the circuit causing the drain. Common culprits include faulty door control modules, the COMAND system, or other electronic control units. Repair or replacement of the faulty component is required.
  • Estimated Cost to Fix: $100 - $1,000+ depending on the source of the drain.
  • Recalls: None Found
• COMAND System Malfunctions
  • Description/Symptoms: The COMAND (Cockpit Management and Data) system, which controls navigation, audio, and other vehicle functions, can experience glitches, freezing, or complete failure.
  • Solution: Software updates may resolve some issues. In other cases, the COMAND unit itself may need to be replaced.
  • Estimated Cost to Fix: $100 (software update) - $2,000+ (replacement).
  • Recalls: None Found

Exterior

• Adaptive Headlight Malfunctions
  • Description/Symptoms: The adaptive headlights, which swivel to improve visibility, can experience malfunctions. Symptoms include the headlights not swiveling properly, error messages on the dash, or uneven headlight beams.
  • Solution: Diagnosis to identify the faulty component, which could be a headlight motor, control module, or wiring issue. Repair or replacement of the faulty part(s) is required.
  • Estimated Cost to Fix: $300 - $1,500+
  • Recalls: None Found

Interior

• Sunroof Issues
  • Description/Symptoms: The sunroof mechanism can experience problems, such as getting stuck, making excessive noise, or failing to open or close properly.
  • Solution: Lubricating the sunroof tracks may resolve minor issues. More serious problems may require replacement of the sunroof motor or entire sunroof assembly.
  • Estimated Cost to Fix: $100 - $1,500+
  • Recalls: None Found

Summary

The 2009 Mercedes-Benz S500 is a luxurious vehicle, but potential owners should be aware of the common issues. The Airmatic suspension and electrical systems are particularly prone to problems and can result in significant repair costs. Oil leaks are also common, although these are usually less expensive to fix. Before purchasing, a thorough inspection by a qualified mechanic is highly recommended to identify any existing or potential problems. While many of these issues are not major, they should be addressed promptly to avoid further damage.