2009 Mercedes-Benz SL500

The 2009 Mercedes-Benz SL500 is a luxurious roadster that offers a blend of performance and comfort. Besides the SL500 with its 5.5L V8 engine producing 382 horsepower and 391 lb-ft of torque, the SL lineup also included the SL550 (also a 5.5L V8 but with more power) and the high-performance SL63 AMG and SL65 AMG variants. What owners typically love about the SL500 is its retractable hardtop, smooth ride, powerful engine, and elegant interior. Common dislikes often revolve around potentially high maintenance costs, complex electronics, and occasional reliability concerns.

Engine

5.5L M273 V8

• Camshaft Adjuster Solenoid (Cam Magnet) Failure
  • Description/Symptoms: Check engine light, rough idling, reduced engine performance. The camshaft adjuster solenoids control the oil flow to the camshaft adjusters which control the valve timing. A faulty solenoid can cause incorrect valve timing.
  • Solution: Replace the faulty camshaft adjuster solenoid.
  • Estimated Cost to Fix: $200 - $400+
• Oil Leaks
  • Description/Symptoms: Oil drips under the car, burning oil smell, low oil level. Common leak areas include valve cover gaskets, oil filter housing gasket, and rear main seal.
  • Solution: Replace the leaking gaskets or seals.
  • Estimated Cost to Fix: $150 - $1000+ depending on the leak location.

Transmission

7G-Tronic 722.9 7-Speed Automatic

• Torque Converter Issues
  • Description/Symptoms: Shuddering during acceleration, especially at low speeds. Can also manifest as harsh shifting.
  • Solution: Replacement of the torque converter. In some cases, a transmission flush and fluid change might temporarily alleviate the symptoms, but replacement is often necessary.
  • Estimated Cost to Fix: $2,000 - $4,000+
• Valve Body Problems
  • Description/Symptoms: Harsh or erratic shifting, transmission slipping, failure to shift into certain gears.
  • Solution: The valve body controls the flow of transmission fluid and can be replaced or rebuilt.
  • Estimated Cost to Fix: $800 - $2,000+

Suspension

• ABC (Active Body Control) Suspension System Leaks/Failure
  • Description/Symptoms: Car sits low on one or more corners, warning lights on the dash, rough ride. The ABC system uses hydraulic fluid and accumulators to control the suspension. Hoses, pumps, and accumulators are prone to leaks and failure.
  • Solution: Identify and repair the leak, replace faulty components (pump, accumulators, valve blocks). System flush and fluid replacement might be necessary.
  • Estimated Cost to Fix: $500 - $3,000+ depending on the component and severity.
• ABC (Active Body Control) Pump Failure
  • Description/Symptoms: Loud whining noise from the pump, suspension malfunctions, ride height issues. The pump provides hydraulic pressure to the ABC system.
  • Solution: Replace the ABC pump.
  • Estimated Cost to Fix: $1,500 - $3,000+

Electrical

• Retractable Hardtop Malfunctions
  • Description/Symptoms: Roof fails to open or close completely, warning lights on the dash, error messages. The retractable hardtop is complex and relies on sensors, hydraulic cylinders, and a control module.
  • Solution: Diagnosis with a Mercedes-Benz specific scan tool to identify faulty sensors, hydraulic issues, or control module problems. Repair or replace the affected components.
  • Estimated Cost to Fix: $500 - $3,000+ depending on the complexity of the issue.
• SAM (Signal Acquisition Module) Failure
  • Description/Symptoms: Various electrical issues, including lighting problems, wiper malfunctions, and starting problems. The SAM modules control various electrical functions of the vehicle.
  • Solution: Diagnosis with a Mercedes-Benz specific scan tool to pinpoint the faulty SAM module. Replacement of the faulty SAM module and reprogramming.
  • Estimated Cost to Fix: $500 - $1,500+
• Battery Drain Issues
  • Description/Symptoms: Battery frequently drains, requiring frequent jump starts.
  • Solution: Diagnose the source of the parasitic draw (faulty module, aftermarket electronics, etc.) and repair or replace the affected component.
  • Estimated Cost to Fix: $100 - $1,000+ depending on the source of the drain.

Exterior

• Retractable Hardtop Seal Leaks
  • Description/Symptoms: Water leaks into the cabin during rain or car washes, especially around the roof seals.
  • Solution: Replace or adjust the weather seals around the retractable hardtop.
  • Estimated Cost to Fix: $100 - $500+

Interior

• Air Conditioning Issues
  • Description/Symptoms: Inadequate cooling, especially on hot days.
  • Solution: Check and recharge the refrigerant. Inspect for leaks in the system. Replace faulty components such as the compressor, condenser, or evaporator.
  • Estimated Cost to Fix: $200 - $1,500+ depending on the issue.
• Seat Control Module Issues
  • Description/Symptoms: Seats not moving, memory functions not working, error messages on the dash.
  • Solution: Diagnose the seat control module and wiring harness. Replace the faulty seat control module.
  • Estimated Cost to Fix: $300 - $1,000+

Recalls

• 2009070003: Recall initiated on July 2009 affecting 2009 SL500. In a crash where a closing force on the occupant’s neck is generated, the neck-pro system may not activate, increasing the risk of injury.

Summary

The 2009 Mercedes-Benz SL500, while a desirable roadster, can present owners with a range of issues. The ABC suspension, electrical components, and retractable hardtop are known to be problematic and can lead to expensive repairs. Engine and transmission issues are also relatively common. Potential buyers should be aware of these common issues and factor in potential maintenance costs when considering purchasing a used SL500. Addressing these issues promptly is essential to ensure the longevity and reliable functionality of the vehicle.