The Mercedes-Benz CLS-Class is a stunning four-door coupe that blends luxury, performance, and style. However, like any vehicle, reliability can vary between model years and generations. Understanding the reliability of different CLS models is crucial for potential buyers seeking a dependable luxury car. This article will delve into the reliability of various CLS models, helping you make an informed decision.
CLS Reliability Comparison Table
| Model Year/Generation | Common Issues | Overall Reliability Score (Out of 5) |
|---|---|---|
| 1st Gen (C219) 2005-2010 | Air suspension problems (especially on CLS500/CLS55 AMG), Sensotronic Brake Control (SBC) system issues (early models), rust, electrical glitches, fuel injector failures, oil leaks (especially around valve cover gaskets), transmission issues (delayed shifting, rough transitions), climate control malfunctions (compressor failure, blend door actuator problems), COMAND system failures, catalytic converter problems. | 3.0 |
| 1st Gen (C219) CLS55 AMG | All of the above, plus: Air suspension issues are more frequent and expensive to repair. Supercharger issues (bearing failure, clutch problems). Engine cooling system problems (leaks, overheating). Brake system components wear out faster due to increased performance. | 2.5 |
| 1st Gen (C219) CLS63 AMG | All of the above, plus: M156 engine "head bolt" issues (can lead to catastrophic engine failure), Camshaft adjuster issues, Oil consumption, Air suspension very prone to failure. Transmission issues (especially under high performance driving). | 2.0 |
| 2nd Gen (C218) 2012-2018 | Air suspension problems (especially on CLS550/CLS63 AMG), fuel injector issues, oil leaks (valve cover, oil filter housing), electrical problems (sensor failures, COMAND system glitches), transmission problems (occasional rough shifting), steering rack issues (leaks, noise), turbocharger issues (on CLS400/CLS63 AMG), coolant leaks, climate control issues. | 3.5 |
| 2nd Gen (C218) CLS63 AMG | All of the above, plus: Air suspension issues are more frequent. Turbocharger failures are more common. Engine cooling system is put under greater stress, leading to leaks and overheating. Transmission issues amplified due to high horsepower. | 3.0 |
| 3rd Gen (C257) 2019-Present | M256 Engine (450 Models) 48V Mild Hybrid System Issues (Battery Failures, System Malfunctions), Electrical problems (software glitches, sensor failures), Suspension issues (air suspension concerns, especially on models equipped with it), COMAND system problems (software bugs, screen malfunctions), fuel pump failures, automatic emergency braking (AEB) system glitches, occasional coolant leaks, transmission software issues. | 4.0 |
| General Maintenance | Regular oil changes, brake maintenance, tire rotations, fluid checks, and adherence to the manufacturer's service schedule are crucial for maintaining reliability across all CLS generations. Ignoring maintenance can exacerbate existing issues and lead to costly repairs. | N/A |
| Preventative Measures | Addressing known issues proactively (e.g., replacing air suspension components preventatively, addressing oil leaks promptly) can significantly improve long-term reliability. Using high-quality parts and fluids is also essential. | N/A |
Detailed Explanations of Common Issues
Air Suspension Problems: Air suspension is a common feature in many CLS models, offering a smooth and comfortable ride. However, it is also a complex system prone to leaks, compressor failures, and sensor issues. These problems can result in a bumpy ride, uneven vehicle height, and expensive repairs. The air suspension is particularly problematic in older models and high-performance AMG variants, which place greater stress on the system.
Sensotronic Brake Control (SBC) System Issues: The SBC system was used in early first-generation CLS models. This system was designed to provide enhanced braking performance, but it proved to be unreliable and expensive to repair. The SBC system is prone to failure, and when it does, it can result in reduced braking power and increased stopping distances. Due to the high cost of repairs, many owners opted to have the system replaced with a traditional braking system.
Rust: Rust is a concern, especially for older CLS models in regions with harsh winters or coastal climates. Common rust-prone areas include the wheel arches, door bottoms, and undercarriage. Rust can compromise the structural integrity of the vehicle and lead to costly repairs. Regularly washing and waxing the car, as well as applying rust inhibitors, can help prevent rust.
Electrical Glitches: Modern cars are heavily reliant on electronic systems, and the CLS is no exception. Electrical glitches can range from minor annoyances, such as malfunctioning sensors, to more serious issues, such as engine management problems. These glitches can be difficult to diagnose and repair, often requiring specialized equipment and expertise.
Fuel Injector Failures: Fuel injectors are responsible for delivering fuel to the engine. Over time, they can become clogged or fail, leading to poor engine performance, reduced fuel economy, and even engine damage. Replacing fuel injectors can be expensive, especially on high-performance AMG models.
Oil Leaks: Oil leaks are a common problem in many cars, and the CLS is no exception. Common leak locations include the valve cover gaskets, oil filter housing, and rear main seal. Oil leaks can lead to reduced engine lubrication, overheating, and eventually engine damage. Regularly checking the oil level and addressing leaks promptly can help prevent these problems.
Transmission Issues: The transmission is responsible for transferring power from the engine to the wheels. Transmission problems can manifest as delayed shifting, rough shifting, or even complete transmission failure. These problems can be caused by worn-out components, low fluid levels, or software glitches. Regular transmission fluid changes can help prevent these issues.
Climate Control Malfunctions: The climate control system is responsible for maintaining a comfortable temperature inside the car. Common problems include compressor failures, blend door actuator problems, and refrigerant leaks. These problems can result in reduced heating or cooling performance and can be expensive to repair.
COMAND System Failures: The COMAND system is Mercedes-Benz's infotainment system, providing access to navigation, audio, and other features. COMAND system failures can range from minor glitches to complete system malfunctions. These problems can be caused by software bugs, hardware failures, or wiring issues.
Catalytic Converter Problems: Catalytic converters are responsible for reducing harmful emissions from the exhaust system. Over time, they can become clogged or fail, leading to reduced engine performance and increased emissions. Replacing catalytic converters can be expensive, especially on high-performance AMG models.
M156 Engine "Head Bolt" Issues: The M156 engine, used in the CLS63 AMG from 2007-2011, is known for a potential "head bolt" issue. The original head bolts were prone to corrosion and failure, which could lead to coolant entering the cylinders and eventually causing catastrophic engine damage. Replacing the head bolts with updated versions is a crucial preventative measure.
Camshaft Adjuster Issues: The M156 engine also experiences camshaft adjuster issues. These adjusters control the timing of the camshafts and can fail over time, leading to reduced engine performance and increased emissions. Replacing the camshaft adjusters can be expensive, requiring specialized tools and expertise.
Oil Consumption (M156 Engine): The M156 engine is known to consume oil at a higher rate than some other engines. This can be due to various factors, including worn valve stem seals or piston rings. Regularly checking the oil level and using high-quality oil can help mitigate this issue.
Steering Rack Issues: The steering rack is a critical component of the steering system. Issues can include leaks, noise, and reduced steering responsiveness. Regular power steering fluid checks and timely repairs can prevent more serious problems.
Turbocharger Issues: Turbochargers, used on models like the CLS400 and CLS63 AMG, increase engine power but can be prone to failure. Common issues include oil leaks, bearing failures, and wastegate problems. Regular maintenance and proper lubrication can help extend the life of the turbochargers.
Coolant Leaks: Coolant leaks can lead to overheating and engine damage. Common leak locations include the radiator, hoses, and water pump. Regularly checking the coolant level and addressing leaks promptly can prevent more serious problems.
M256 Engine (450 Models) 48V Mild Hybrid System Issues: The M256 engine, found in the 450 models of the third-generation CLS, uses a 48V mild hybrid system. This system can experience issues such as battery failures and system malfunctions, which can affect the car's performance and fuel economy. Software updates and proper maintenance are crucial for ensuring the system's reliability.
Automatic Emergency Braking (AEB) System Glitches: The AEB system is designed to automatically apply the brakes in the event of an imminent collision. However, glitches in the system can cause it to activate unnecessarily or fail to activate when needed. Regular software updates and sensor calibrations are essential for ensuring the system's reliability.
General Maintenance: Regular maintenance is crucial for maintaining the reliability of any car, including the CLS. This includes regular oil changes, brake maintenance, tire rotations, and fluid checks. Adhering to the manufacturer's service schedule can help prevent many common problems and extend the life of the car.
Preventative Measures: Taking preventative measures can also help improve the long-term reliability of the CLS. This includes addressing known issues proactively, such as replacing air suspension components preventatively or addressing oil leaks promptly. Using high-quality parts and fluids is also essential.
Frequently Asked Questions
Which CLS model year is the most reliable?
The third-generation (C257) CLS models from 2019 onwards generally exhibit better reliability due to advancements in technology and improved manufacturing processes.
Are AMG models less reliable than standard CLS models?
Yes, AMG models often have lower reliability due to the increased stress on their components from higher performance.
How often should I change the oil in my CLS?
It's recommended to change the oil every 7,500 to 10,000 miles, or according to the manufacturer's recommendations, using synthetic oil.
Are air suspension problems common in the CLS?
Yes, air suspension problems are a common issue, especially in older models and those equipped with the Airmatic system.
What should I look for when buying a used CLS?
Check for signs of rust, oil leaks, air suspension problems, and ensure the car has a complete service history. Pay close attention to the COMAND system's functionality and any error messages.
Conclusion
Choosing the most reliable CLS requires careful consideration of the model year, engine type, and maintenance history. While the third-generation models generally offer better reliability, regular maintenance and preventative measures are essential for ensuring the long-term dependability of any CLS. By understanding the common issues associated with each model and taking proactive steps to address them, you can enjoy the luxury and performance of the CLS with greater peace of mind.