2006 Mercedes-Benz S430

The 2006 Mercedes-Benz S430 is a luxury sedan that offers a smooth ride and a comfortable interior. The S430 came standard with a 4.3L V8 engine that produced 275 horsepower and 295 lb-ft of torque. Other engine options included the 5.0L V8 in the S500, the 5.5L V12 in the S600, and the AMG tuned 5.4L V8 in the S55 AMG. All engines were paired with a 7-speed automatic transmission. Owners often praise the S430 for its luxurious features and ride quality, but common complaints include expensive maintenance and repairs, particularly with the air suspension system and electronics.

Engine

4.3L M113 V8

• Oil Leaks
  • Description/Symptoms: Oil leaks are common from various locations, including the valve cover gaskets, oil filter housing gasket, and rear main seal. This can result in oil consumption, visible oil on the engine, and a burning oil smell.
  • Solution: Replace the leaking gaskets or seals.
  • Estimated Cost to Fix: $200 - $800+ depending on the location of the leak and labor costs.
  • Recalls: None Found
• Mass Air Flow (MAF) Sensor Failure
  • Description/Symptoms: The MAF sensor can fail, causing poor engine performance, rough idling, and a check engine light.
  • Solution: Replace the MAF sensor.
  • Estimated Cost to Fix: $150 - $300
  • Recalls: None Found

Transmission

722.9 7-Speed Automatic

• Valve Body Issues
  • Description/Symptoms: The 722.9 transmission is known to have issues with the valve body, leading to harsh shifting, delayed engagement, and potentially complete transmission failure. Early versions of the 722.9 transmission were more prone to valve body failure.
  • Solution: Replacement of the valve body or a transmission rebuild.
  • Estimated Cost to Fix: $800 - $3000+
  • Recalls: None Found
• Conductor Plate Failure
  • Description/Symptoms: The conductor plate, located inside the transmission, can fail, causing erratic shifting, limp mode, and a check engine light.
  • Solution: Replace the conductor plate.
  • Estimated Cost to Fix: $500 - $1200
  • Recalls: None Found

Suspension

• Airmatic Air Suspension Failure
  • Description/Symptoms: The Airmatic air suspension system is notorious for failures. Common issues include leaking air struts, a failing air compressor, and faulty sensors. This can lead to the car sitting unevenly, a harsh ride, and a “Visit Workshop” message on the dashboard.
  • Solution: Replace the faulty air struts, air compressor, or sensors. Sometimes, a full system overhaul is necessary.
  • Estimated Cost to Fix: $800 - $2000+ per strut; $500 - $1000+ for the compressor.
  • Recalls: None Found

Electrical

• SAM (Signal Acquisition Module) Failure
  • Description/Symptoms: SAM modules control various electrical functions. Failure can cause a wide range of issues, including problems with the lights, wipers, power windows, and door locks.
  • Solution: Replace the faulty SAM module and program it to the vehicle.
  • Estimated Cost to Fix: $500 - $1500+ depending on the specific SAM module.
  • Recalls: None Found
• Battery Drain
  • Description/Symptoms: Excessive battery drain can be caused by a number of issues, including a faulty alternator, parasitic drain from a malfunctioning module, or a bad battery.
  • Solution: Diagnose the source of the drain and replace the faulty component or battery.
  • Estimated Cost to Fix: $100 - $500+ depending on the issue.
  • Recalls: None Found

Exterior

• Rust
  • Description/Symptoms: Rust can occur in various locations, especially in areas with road salt exposure. Common areas include the wheel wells, rocker panels, and door edges.
  • Solution: Rust repair or panel replacement.
  • Estimated Cost to Fix: $300 - $2000+ depending on the severity.
  • Recalls: None Found

Interior

• Sunroof Issues
  • Description/Symptoms: Sunroofs can experience problems with the motor, tracks, or seals. This can lead to the sunroof not opening or closing properly, or leaking water into the cabin.
  • Solution: Repair or replace the sunroof motor, tracks, or seals.
  • Estimated Cost to Fix: $300 - $1000+
  • Recalls: None Found
• Display Screen Pixelation/Failure
  • Description/Symptoms: The COMAND system display screen can experience pixelation or complete failure over time.
  • Solution: Replace the display screen or the entire COMAND unit.
  • Estimated Cost to Fix: $500 - $2000+
  • Recalls: None Found

Summary

The 2006 Mercedes-Benz S430 is a luxurious vehicle that can be prone to a number of costly issues. The most significant problems revolve around the Airmatic suspension, electrical components (SAM modules), and the 7-speed transmission. Engine oil leaks are also common but are generally less expensive to address. The potential for high repair costs makes pre-purchase inspection especially important.