2005 Mercedes-Benz SL55 AMG

The 2005 Mercedes-Benz SL55 AMG is a high-performance roadster known for its exhilarating power and luxurious features. It came standard with a supercharged 5.4-liter V8 engine producing 493 horsepower and 516 lb-ft of torque. While other SL models offered different engines, including a V6 and naturally aspirated V8, the SL55 AMG was exclusively equipped with the supercharged V8. All models were paired with a 5-speed automatic transmission. Owners often praise the car’s incredible acceleration and comfortable ride, but common complaints include high maintenance costs and potential issues with the complex electronic systems.

Engine

5.4L Supercharged V8

• Intercooler Pump Failure
  • Description/Symptoms: Loss of power, especially during acceleration, due to reduced cooling of the intake air. Can trigger a check engine light.
  • Solution: Replacement of the intercooler pump.
  • Estimated Cost to Fix: $300 - $600
• Supercharger Clutch Failure
  • Description/Symptoms: Whining noise from the engine, decreased power output, and potential for supercharger failure.
  • Solution: Replacement of the supercharger clutch.
  • Estimated Cost to Fix: $800 - $1500+
• Valve Cover Gasket Leaks
  • Description/Symptoms: Oil leaks around the valve covers, causing a burning smell.
  • Solution: Replacement of the valve cover gaskets.
  • Estimated Cost to Fix: $300 - $800

Transmission

5-Speed Automatic

• Valve Body Issues
  • Description/Symptoms: Harsh or delayed shifting, slipping between gears, and possible transmission failure.
  • Solution: Valve body replacement or rebuild.
  • Estimated Cost to Fix: $800 - $2500+
• Torque Converter Failure
  • Description/Symptoms: Shuddering or vibration at low speeds, especially when accelerating from a stop. Can cause transmission codes.
  • Solution: Torque converter replacement.
  • Estimated Cost to Fix: $1000 - $3000+

Suspension

• ABC (Active Body Control) System Leaks and Failure
  • Description/Symptoms: The ABC system maintains a level ride height and reduces body roll. Leaks often occur at the valve blocks, struts, or pump. Warning messages on the dash such as “ABC Visit Workshop” and sagging suspension are common. System failure can lead to a very bouncy or stiff ride.
  • Solution: Repair or replacement of leaking components (hoses, valve blocks, struts, or pump). System flush.
  • Estimated Cost to Fix: $500 - $2000+ per component, system flush $300 - $500
• ABC Pump Failure
  • Description/Symptoms: Whining noise from the pump, suspension not raising or lowering properly, and ABC warning lights.
  • Solution: ABC Pump replacement.
  • Estimated Cost to Fix: $1500 - $3000+

Electrical

• SAM (Signal Acquisition Module) Failure
  • Description/Symptoms: Various electrical issues, including lights not working, wipers malfunctioning, and starting problems. Multiple error codes may be present.
  • Solution: SAM unit replacement and programming.
  • Estimated Cost to Fix: $800 - $2000+
• Battery Drain
  • Description/Symptoms: The car’s battery drains quickly, especially if left unused for a few days.
  • Solution: Diagnose and repair the source of the drain (often related to faulty modules or aftermarket accessories).
  • Estimated Cost to Fix: $100 - $500+ (diagnosis) + repair cost.
• Convertible Top Malfunctions
  • Description/Symptoms: The convertible top may fail to open or close properly, or may stop mid-cycle. Common causes are hydraulic leaks, sensor failures, or a faulty control module.
  • Solution: Diagnose the cause of the malfunction and repair or replace the faulty components.
  • Estimated Cost to Fix: $500 - $3000+ depending on the issue.

Exterior

• Convertible Top Hydraulic Leaks
  • Description/Symptoms: Leaks can be seen at the hydraulic cylinders or hoses. This will cause the top to be inoperable.
  • Solution: Replace hydraulic cylinders or hoses.
  • Estimated Cost to Fix: $500 - $3000+

Interior

• COMAND System Issues
  • Description/Symptoms: Navigation, radio, and other COMAND functions may malfunction or become unresponsive. Screen flickering or dimming can also occur.
  • Solution: Repair or replacement of the COMAND unit.
  • Estimated Cost to Fix: $500 - $2000+

Summary

The 2005 Mercedes-Benz SL55 AMG offers impressive performance but can be plagued by various issues, particularly with the ABC suspension, electrical systems, and powertrain components. Repairs can be expensive due to the complexity of the car and the cost of replacement parts. Potential buyers should be aware of these potential problems and factor them into their ownership costs. Pre-purchase inspections by a qualified Mercedes-Benz mechanic are highly recommended.