2007 Mercedes-Benz S550

2007 Mercedes-Benz S550

Overview

The 2007 Mercedes-Benz S550, representing the W221 generation, is a luxury sedan known for its advanced technology and comfortable ride. Powered by a potent 5.5-liter V8 engine, it offers strong performance. While generally well-regarded for its build quality and sophisticated features, like any complex vehicle, it can experience specific issues as it ages. This analysis focuses on documented common problems beyond routine maintenance, providing insights into potential areas of concern for owners and prospective buyers. The focus is on components that have shown a tendency for failure or significant repair needs.

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Engine

5.5L V8 (M273)

Timing Chain Tensioner Wear

• Symptoms: Rattling noise from the engine, especially on startup; check engine light.
• Solution: Replacement of timing chain tensioners, guides, and potentially the chain itself.
• Cost: $1,500 - $3,000

Intake Manifold Flap Actuator Failure

• Symptoms: Check engine light, rough idle, reduced engine power, P2004/P2005/P2006 codes.
• Solution: Replacement of the intake manifold or repair/replacement of the actuator.
• Cost: $500 - $1,200

Transmission

7G-TRONIC (722.9) Automatic Transmission

Valve Body Issues

• Symptoms: Harsh shifting, delayed engagement, slipping gears, transmission warning light.
• Solution: Repair or replacement of the valve body assembly.
• Cost: $1,000 - $2,500

Torque Converter Problems

• Symptoms: Shuddering at low speeds, slipping, rough engagement.
• Solution: Replacement of the torque converter.
• Cost: $800 - $1,800

Suspension

ABC (Active Body Control) Suspension

Hydraulic Leaks

• Symptoms: Vehicle sagging, ‘ABC system visit workshop’ warning message, fluid leaks under the car.
• Solution: Repair or replacement of leaking hoses, struts, or the ABC pump.
• Cost: $1,000 - $4,000+

Pump Failure

• Symptoms: Loss of suspension height control, loud whining noise from the pump, ‘ABC system visit workshop’ warning.
• Solution: Replacement of the ABC hydraulic pump.
• Cost: $1,200 - $2,500

Standard Air Suspension (if equipped)

Air Spring Leaks

• Symptoms: Vehicle sagging on one or more corners, compressor running excessively, ‘level control system’ warning.
• Solution: Replacement of leaking air springs or air struts.
• Cost: $600 - $1,500 per corner

Electrical

EIS (Electronic Ignition Switch)

Failure

• Symptoms: Key not recognized, car won’t start, steering wheel lock issues.
• Solution: Replacement of the EIS module.
• Cost: $500 - $1,000

SAM (Signal Acquisition Module) Issues

Corrosion/Water Intrusion

• Symptoms: Various electrical gremlins, malfunctioning lights, power windows, or other accessories.
• Solution: Repair or replacement of the SAM module and addressing the source of water intrusion.
• Cost: $400 - $1,500

Headlight Ballast/Bulb Failure

Xenon Headlight Malfunction

• Symptoms: One or both headlights not working, flickering.
• Solution: Replacement of ballast or xenon bulb.
• Cost: $200 - $600

Exterior

Door Handle Mechanism

Sticking/Failure

• Symptoms: Exterior door handles not retracting or releasing properly.
• Solution: Lubrication or replacement of the door handle mechanism.
• Cost: $200 - $500

Sunroof Drain Tubes

Clogging

• Symptoms: Water leaks into the cabin, particularly around the headliner and A-pillars, potentially affecting electrical components.
• Solution: Clearing of drain tubes and potentially repairing water damage.
• Cost: $150 - $400

Interior

Seat Control Modules

Malfunction

• Symptoms: Power seats not moving, memory functions failing, seat heating/cooling issues.
• Solution: Diagnosis and replacement of faulty seat control modules or wiring.
• Cost: $300 - $800

COMAND Navigation System

Screen/Unit Failure

• Symptoms: Navigation screen not turning on, freezing, or other infotainment system glitches.
• Solution: Software updates or replacement of the COMAND unit.
• Cost: $500 - $2,000+

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Summary Verdict

The 2007 Mercedes-Benz S550 is a luxurious and powerful vehicle, but its advanced systems can lead to significant repair costs as it ages. Key areas to monitor include the engine’s timing chain tensioners and intake manifold, the 7-speed transmission’s valve body and torque converter, and especially the complex Active Body Control (ABC) suspension system, which is prone to hydraulic leaks and pump failures. Electrical issues, particularly with the EIS and SAM modules, are also common. While the interior and exterior are generally robust, minor issues like door handles and sunroof drains can arise. Prospective buyers should be prepared for potentially high maintenance and repair bills, especially concerning the suspension and complex electronics.