2004 Mercedes-Benz SL500

The 2004 Mercedes-Benz SL500 is a luxurious roadster known for its retractable hardtop, powerful engine, and comfortable ride. The SL500 came standard with a 5.0-liter V8 engine producing 302 horsepower and 339 lb-ft of torque, paired with a 5-speed automatic transmission. A more powerful SL55 AMG version was also available, but we will focus on the standard SL500. Owners often praise the car’s elegant styling, comfortable interior, and strong performance, but some common complaints include the complex electronic systems, potential for high repair costs, and occasional issues with the hydraulic systems.

Engine

5.0L M113 V8

• Valve Cover Gasket Leaks
  • Description/Symptoms: Oil leaks from the valve cover gaskets, often noticeable as oil drips or a burning smell.
  • Solution: Replacement of the valve cover gaskets.
  • Estimated Cost to Fix: $200 - $400
  • Recalls: None Found
• MAF (Mass Air Flow) Sensor Failure
  • Description/Symptoms: Rough idling, poor acceleration, and potential stalling. Check engine light will often illuminate.
  • Solution: Replacement of the MAF sensor.
  • Estimated Cost to Fix: $200 - $400
  • Recalls: None Found
• Harmonic Balancer Failure
  • Description/Symptoms: Vibrations, noise, or visible cracking/separation of the harmonic balancer.
  • Solution: Replacement of the harmonic balancer.
  • Estimated Cost to Fix: $400 - $800
  • Recalls: None Found

Transmission

5-Speed Automatic (722.6)

• Transmission Conductor Plate Failure
  • Description/Symptoms: Erratic shifting, getting stuck in gear, or complete loss of gear engagement.
  • Solution: Replacement of the transmission conductor plate, often combined with a fluid and filter service.
  • Estimated Cost to Fix: $800 - $1500
  • Recalls: None Found
• Slipping
  • Description/Symptoms: The transmission is not properly engaging the correct gear and causing the vehicle to slip while accelerating.
  • Solution: Full transmission rebuild, or replacement of the entire transmission.
  • Estimated Cost to Fix: $3000 - $6000
  • Recalls: None Found

Suspension

• ABC (Active Body Control) Suspension Issues
  • Description/Symptoms: Sagging suspension, warning lights on the dash, a harsh ride, or hydraulic fluid leaks.
  • Solution: Diagnosis and repair of the ABC system, which could involve replacing accumulators, pumps, valve blocks, or struts. Flushing the ABC system may help with minor issues.
  • Estimated Cost to Fix: $500 - $3000+ (depending on the component needing replacement)
  • Recalls: None Found

Electrical

• EIS (Electronic Ignition Switch) Failure
  • Description/Symptoms: Difficulty starting the car, key not being recognized, or complete failure to start.
  • Solution: Replacement of the EIS module, which often requires programming to the vehicle.
  • Estimated Cost to Fix: $800 - $1500
  • Recalls: None Found
• SAM (Signal Acquisition Module) Failure
  • Description/Symptoms: Various electrical malfunctions, such as lights not working, wipers malfunctioning, or other seemingly random electrical issues.
  • Solution: Diagnosis to determine which SAM is faulty (front or rear) and replacement of the module. Programming may be required.
  • Estimated Cost to Fix: $500 - $1200
  • Recalls: None Found
• Battery Drain
  • Description/Symptoms: Battery constantly dying or needing to be jumped.
  • Solution: Perform a parasitic draw test and locate which circuit is causing the draw.
  • Estimated Cost to Fix: $100 - $500+ depending on where the draw is coming from
  • Recalls: None Found

Exterior

• Retractable Hardtop Malfunctions
  • Description/Symptoms: The roof failing to open or close properly, getting stuck mid-cycle, or hydraulic fluid leaks.
  • Solution: Diagnosis of the hydraulic system and repair or replacement of faulty components, such as pumps, cylinders, or sensors.
  • Estimated Cost to Fix: $500 - $3000+ (depending on the component needing replacement)
  • Recalls: None Found

Interior

• Instrument Cluster Pixelation
  • Description/Symptoms: Pixels disappearing or fading on the instrument cluster display, making it difficult to read information.
  • Solution: Repair or replacement of the instrument cluster. Some shops specialize in repairing the pixelation issue.
  • Estimated Cost to Fix: $300 - $800
  • Recalls: None Found

Summary

The 2004 Mercedes-Benz SL500, while offering luxury and performance, is prone to several common issues. The ABC suspension, electrical gremlins, and retractable hardtop malfunctions can lead to significant repair costs. Engine and transmission issues, while less frequent, can also be expensive to address. Potential buyers should be aware of these potential problems and factor in maintenance costs when considering this vehicle. The severity of these issues varies, but many can result in high repair bills, making a thorough pre-purchase inspection crucial.