The Mercedes-Benz S-Class W220 S 600 is a flagship luxury sedan, admired for its cutting-edge technology, superior comfort, and V12 engine. However, as advanced as it may be, the W220 S 600 is not free from mechanical and electrical issues. Owners of this model often encounter a variety of problems, ranging from minor inconveniences to significant mechanical failures. This in-depth article delves into the common problems of the W220 S 600, their causes, and practical solutions, ensuring that owners are well-informed and equipped to maintain their vehicles effectively.
Mercedes S-Class W220 S 600 Engine Performance Issues
The W220 S 600 is powered by a robust 5.5-liter twin-turbocharged V12 engine, which offers an exceptional blend of power and refinement. While the engine is a marvel of engineering, it is also one of the most complex and expensive components to repair. Over time, various issues can arise, compromising its performance.
One of the most reported engine issues is oil leaks. Given the size and complexity of the V12 engine, oil leaks can occur at various points, including the valve cover gaskets, turbocharger seals, and oil cooler lines. Symptoms of oil leaks include visible oil stains under the car, a burning oil smell, and low oil levels. The primary cause of oil leaks is the degradation of rubber gaskets and seals, which harden and lose their sealing properties over time due to heat and pressure. Addressing oil leaks requires a detailed inspection to identify the source. Replacing the faulty gaskets or seals is essential, and for turbo-related leaks, rebuilding or replacing the turbocharger may be necessary. Regular oil changes using high-quality synthetic oil can help prevent such issues.
Misfiring is another common problem with the V12 engine. Owners often report rough idling, poor acceleration, or a check engine light. Misfires are typically caused by failing ignition coil packs, which are responsible for delivering electrical power to the spark plugs. Given that the S 600’s V12 engine has 12 cylinders, the cost of replacing all the coil packs can be significant. Worn spark plugs, clogged fuel injectors, or a failing Mass Air Flow (MAF) sensor can also contribute to misfiring. Resolving this issue involves replacing the faulty components, such as the ignition coils or spark plugs, and ensuring regular maintenance to avoid future occurrences.
Mercedes S-Class W220 S 600 Transmission Problems
The W220 S 600 is equipped with a 5-speed automatic transmission that provides smooth and seamless gear shifts. However, as with any aging vehicle, transmission issues can develop over time.
A common complaint among owners is hard or delayed shifting. This problem often arises due to a failing conductor plate, which is part of the transmission’s control system. The conductor plate contains sensors that monitor gear selection and fluid temperature, and when it fails, the transmission may struggle to shift properly. Another potential cause is the buildup of contaminants in the transmission fluid, which can clog the valve body and disrupt the hydraulic flow. Resolving this issue involves replacing the conductor plate or valve body, as well as performing a complete transmission fluid and filter change.
Torque converter failure is another significant concern for the W220 S 600’s transmission. The torque converter plays a crucial role in transferring power from the engine to the transmission. Symptoms of a failing torque converter include shuddering during acceleration, slipping gears, or unusual vibrations. The most common cause of torque converter failure is wear and tear over time. Replacing the torque converter is necessary to restore smooth transmission operation. Regular transmission maintenance, including timely fluid changes, can prevent such failures.
Mercedes S-Class W220 S 600 Suspension and Steering Problems
The W220 S 600 features the advanced Airmatic suspension system, which provides an unparalleled level of comfort and ride quality. However, the complexity of this system makes it prone to a variety of problems.
One of the most frequent issues is air suspension failure. The Airmatic system relies on air struts, an air compressor, and associated sensors to maintain ride height and adapt to road conditions. Over time, the air struts can develop leaks, causing the suspension to sag or fail entirely. Additionally, the compressor can burn out from overuse if it is constantly working to compensate for leaks. Symptoms of Airmatic suspension failure include a noticeable drop in ride height, uneven suspension, or a dashboard warning light. Fixing this issue involves replacing the faulty air struts or compressor. For a more cost-effective solution, many owners opt to convert the air suspension to traditional coil springs, though this sacrifices some of the ride comfort and adaptability.
Steering problems are also common in the W220 S 600, particularly issues with the steering rack and tie rods. Worn tie rods can cause clunking noises, loose steering, or uneven tire wear. The steering rack, which is responsible for directing the wheels, can develop leaks or internal damage, leading to stiff or unresponsive steering. Addressing these problems requires replacing the worn tie rods or steering rack. Regular inspections of the steering components can catch early signs of wear, preventing further damage.
Mercedes S-Class W220 S 600 Electrical System Problems
The W220 S 600 is equipped with one of the most advanced electrical systems of its time, featuring numerous sensors, modules, and luxury features. While these systems enhance the driving experience, they are also a source of frequent headaches for owners.
Battery drain is a widespread issue reported by many W220 owners. The S 600’s complex electrical network includes features like heated seats, an advanced infotainment system, and adaptive lighting, all of which can contribute to parasitic draws on the battery. Faulty modules, such as the Command infotainment system or the rear SAM (Signal Acquisition Module), are common culprits. Symptoms of battery drain include difficulty starting the car or a completely dead battery after leaving the vehicle parked overnight. Diagnosing the source of the drain involves testing for excessive current draw and identifying the faulty component. Replacing or repairing the affected module usually resolves the issue. To prevent battery drain, ensure that all accessories are turned off when the vehicle is parked, and consider using a trickle charger if the car is not driven frequently.
Failures in the Command infotainment system are another common complaint. The system, which controls audio, navigation, and climate settings, may freeze, become unresponsive, or fail entirely. These problems are often caused by outdated software or internal hardware faults. Resolving Command system failures may involve performing a software update, repairing the control unit, or replacing the system entirely.
Mercedes S-Class W220 S 600 Cooling System Problems
The cooling system in the Mercedes S-Class W220 S 600 is essential for maintaining the V12 engine’s performance and preventing overheating. However, several components in this system are prone to failure over time, leading to common complaints from owners.
Radiator leaks are a frequent issue in the W220 S 600, particularly as the vehicle ages. The radiator is responsible for dissipating heat from the engine coolant, but it can develop leaks due to corrosion, cracks, or physical damage. Corrosion is often the result of using low-quality or improperly mixed coolant, which allows contaminants to accumulate and degrade the radiator's internal structure. Cracks or punctures can also occur from debris hitting the radiator or the natural expansion and contraction of materials over time. Symptoms of radiator leaks include coolant puddles under the car, engine overheating, and a noticeable drop in coolant levels. Resolving this problem typically involves replacing the radiator entirely, as patching leaks is only a temporary solution. To prevent future issues, owners should perform regular coolant flushes using high-quality, manufacturer-recommended coolant.
Another common cooling system problem is thermostat and water pump failure. The thermostat regulates the flow of coolant, while the water pump ensures that coolant circulates efficiently through the engine. When the thermostat fails, it can become stuck in the open or closed position. A stuck-open thermostat may cause the engine to run too cool, reducing efficiency, while a stuck-closed thermostat can lead to dangerous overheating. Similarly, a failing water pump, often due to a worn-out impeller or bearing, can lead to insufficient coolant flow and overheating. Symptoms of these issues include fluctuating engine temperatures, coolant leaks near the pump, and unusual noises from the engine bay. Resolving these problems requires replacing the faulty thermostat or water pump. Regular inspections and timely maintenance can prevent cooling system failures and protect the engine from overheating.
Mercedes S-Class W220 S 600 Interior and Comfort Problems
The W220 S 600 offers a luxurious interior with advanced features designed for maximum comfort, but certain components can wear out or malfunction, impacting the overall experience. Two of the most common interior problems are seat adjustment failures and climate control system issues.
Seat adjustment failures are a frequent annoyance for S 600 owners. The power-adjustable seats, which allow drivers and passengers to customize their seating position, may stop working over time. This issue is often caused by faulty seat motors or damaged wiring. In some cases, moisture intrusion can corrode electrical connections, leading to intermittent functionality or complete failure. Diagnosing and repairing the problem requires replacing the faulty motor or repairing the wiring. Keeping the interior dry and avoiding excessive force when adjusting seats can help prolong the life of these components.
The climate control system in the W220 S 600 is another source of frustration for many owners. Designed to provide dual-zone temperature control, the system may develop issues such as inconsistent cooling or heating, weak airflow, or unusual noises from the vents. These problems are typically caused by a failing blower motor, clogged cabin air filters, or refrigerant leaks. Electrical faults in the climate control module can also contribute to malfunctions. Fixing these issues involves replacing the blower motor, cleaning or replacing the cabin air filters, and repairing refrigerant leaks. If the control module is at fault, reprogramming or replacement may be necessary. Regular maintenance, including checking refrigerant levels and replacing filters, can keep the climate control system operating efficiently.
Mercedes S-Class W220 S 600 Premature Rusting
Rust is a well-documented issue in the W220 series, including the S 600. While the car’s bodywork is designed to resist corrosion, many owners report premature rusting in specific areas, such as the wheel arches, door sills, and trunk edges. Left untreated, rust can spread and compromise the structural integrity of the vehicle.
The primary cause of rust is poor drainage design, which allows water and debris to accumulate in areas prone to corrosion. Additionally, exposure to road salt in winter can accelerate the rusting process. Rust often begins as small spots that may go unnoticed until significant damage has occurred. Addressing rust requires sanding down the affected areas, applying rust inhibitors, and repainting to restore the vehicle’s appearance and protection. For advanced cases, replacing rusted panels may be necessary. To prevent rust, owners should regularly wash their vehicles, especially during winter, and consider applying an underbody rust-proofing treatment.
Mercedes S-Class W220 S 600 Electrical System Problems
Beyond the common battery drain and Command system failures, the W220 S 600 is also prone to issues with its complex lighting and sensor systems. Adaptive headlights, which adjust based on steering input and road conditions, are a highlight of the S 600 but are often plagued by malfunctions. Owners may notice the headlights failing to adjust properly or becoming stuck in one position. These problems are usually caused by faulty headlight motors, damaged wiring, or sensor failures. Repairing the system involves diagnosing the faulty component and replacing it as needed. Keeping the headlight assemblies clean and free of moisture can help prevent future issues.
Another common electrical problem is the failure of the rear SAM (Signal Acquisition Module). The SAM controls various rear-end electrical functions, including taillights, brake lights, and the trunk release mechanism. When the SAM fails, owners may experience intermittent or complete loss of these functions. This issue is often caused by water intrusion or electrical short circuits. Fixing the problem involves replacing the faulty SAM unit and addressing any underlying water leaks to prevent recurrence.
Mercedes S-Class W220 S 600 Sensotronic Brake Control (SBC) System Problems
The Sensotronic Brake Control (SBC) system, a hallmark of the W220 series, provides electronically controlled braking for improved precision and performance. However, it is also one of the most problematic systems in the S 600. Owners frequently report warning messages on the dashboard indicating SBC malfunctions. In severe cases, the braking system may enter a fail-safe mode, reducing braking power and increasing stopping distances.
The SBC system fails primarily due to wear on the hydraulic pump and electronic control module. Mercedes-Benz issued recalls for certain W220 models to address SBC-related issues, offering free replacements for affected vehicles. For those not covered by the recall, replacing the SBC pump or module is necessary to restore full braking functionality. Regular inspections and software updates can help prolong the life of the SBC system and ensure reliable braking performance.
Conclusion
The Mercedes-Benz S-Class W220 S 600 is a luxurious and technologically advanced vehicle, but it comes with its share of common problems. From engine and transmission issues to suspension, electrical, and rust concerns, understanding these problems is crucial for maintaining the car’s performance and longevity. Addressing issues promptly, performing regular maintenance, and seeking professional repairs can help preserve the luxury and reliability of this flagship model.
For expert assistance with diagnosing and repairing your Mercedes S-Class W220 S 600, visit European Auto Pro, 253 Goodwood Road, Kings Park, 5034 South Australia. Their team of experienced technicians specializes in Mercedes-Benz vehicles, providing reliable service to keep your car running at its best.