2008 Mercedes-Benz S500

The 2008 Mercedes-Benz S500 is a luxury sedan known for its smooth ride, opulent interior, and advanced technology for its time. The S500 came standard with a 5.5L V8 engine producing 382 horsepower and 391 lb-ft of torque. While this was the standard engine for the US market, other markets had other options available. Owners generally appreciate the car’s comfort, quietness, and prestige. Common complaints often revolve around the high cost of maintenance and repairs, as well as the complexity of the electronics.

Engine

5.5L M273 V8

• Oil Leaks from Valve Cover Gaskets
  • Description/Symptoms: Oil leaks from the valve cover gaskets, leading to oil drips on exhaust manifolds and potential burning smells. Visible oil around the valve covers.
  • Solution: Replacement of the valve cover gaskets.
  • Estimated Cost to Fix: $400 - $800+
  • Recalls: None Found
• Camshaft Adjuster Solenoid Failure
  • Description/Symptoms: Check engine light illuminated, rough idle, and potential loss of power. Diagnostic codes related to camshaft position or timing.
  • Solution: Replacement of the faulty camshaft adjuster solenoid.
  • Estimated Cost to Fix: $200 - $500+
  • Recalls: None Found
• Secondary Air Injection System Failure
  • Description/Symptoms: Check engine light illuminated, often with codes related to the secondary air injection system. Loud noise during cold starts, or failure to pass emissions tests.
  • Solution: Diagnosis and repair or replacement of the faulty components, such as the air pump or valve.
  • Estimated Cost to Fix: $300 - $800+
  • Recalls: None Found

Transmission

7G-Tronic (722.9) 7-Speed Automatic

• Torque Converter Failure
  • Description/Symptoms: Shuddering or vibration during acceleration, particularly at lower speeds. Hesitation when shifting gears.
  • Solution: Replacement of the torque converter.
  • Estimated Cost to Fix: $1500 - $3500+
  • Recalls: None Found
• Valve Body Issues
  • Description/Symptoms: Hard or erratic shifting, delayed engagement of gears, or slipping between gears.
  • Solution: Replacement or rebuild of the valve body.
  • Estimated Cost to Fix: $800 - $2000+
  • Recalls: None Found
• Conductor Plate Failure
  • Description/Symptoms: Transmission going into limp mode (stuck in a single gear), inability to shift gears, and diagnostic codes related to the conductor plate.
  • Solution: Replacement of the conductor plate.
  • Estimated Cost to Fix: $800 - $1500+
  • Recalls: None Found

Suspension

• Airmatic Suspension Compressor Failure
  • Description/Symptoms: The car sitting low, especially overnight. The Airmatic system malfunction warning light is illuminated. The car may not raise to the proper ride height.
  • Solution: Replacement of the airmatic compressor.
  • Estimated Cost to Fix: $800 - $1500+
  • Recalls: None Found
• Airmatic Strut Failure
  • Description/Symptoms: Leaking air from the struts, causing the vehicle to sag on one or more corners. Rough ride quality and potential for system malfunction warnings.
  • Solution: Replacement of the faulty Airmatic strut(s).
  • Estimated Cost to Fix: $1000 - $2000+ per strut
  • Recalls: None Found

Electrical

• Battery Drain Issues
  • Description/Symptoms: Dead battery, especially after the car has been sitting for a few days. Difficulty starting the car.
  • Solution: Diagnosis and repair of the source of the parasitic drain, which could be a faulty module or component.
  • Estimated Cost to Fix: $200 - $1000+ (depending on the source of the drain)
  • Recalls: None Found
• SAM (Signal Acquisition Module) Failure
  • Description/Symptoms: Multiple electrical issues, such as lights not working, wipers malfunctioning, or issues with the instrument cluster. Diagnostic codes related to the SAM module.
  • Solution: Replacement or reprogramming of the faulty SAM module.
  • Estimated Cost to Fix: $500 - $1500+
  • Recalls: None Found
• COMAND System Malfunctions
  • Description/Symptoms: Freezing, Crashing, or otherwise acting up
  • Solution: Most likely will require a full replacement of the unit.
  • Estimated Cost to Fix: $1000+
  • Recalls: None Found

Exterior

• Sunroof Issues
  • Description/Symptoms: Sunroof failing to open or close properly, making unusual noises, or leaking water.
  • Solution: Diagnosis and repair of the sunroof mechanism, which may involve replacing damaged parts or realigning the sunroof.
  • Estimated Cost to Fix: $300 - $1000+
  • Recalls: None Found

Interior

• Seat Control Switch Failure
  • Description/Symptoms: The seat failing to move in one or more directions, or the seat controls not responding at all.
  • Solution: Replacement of the faulty seat control switch.
  • Estimated Cost to Fix: $200 - $500+
  • Recalls: None Found

Summary

The 2008 Mercedes-Benz S500, while luxurious, is prone to various issues, especially related to its complex electrical and suspension systems. The Airmatic suspension and electrical gremlins are common, and repairs can be costly. Engine and transmission issues, while less frequent, can also be expensive to address. Potential buyers should be aware of these potential issues and budget accordingly for maintenance and repairs. The severity of the issues ranges from minor inconveniences to major mechanical failures, and the cost of repairs can range from a few hundred dollars to several thousand, making pre-purchase inspection crucial.