The fourth-generation Mercedes-Benz C-class with the W205 body, especially in its updated version, represents the embodiment of a modern approach to creating premium compact sedans. Developed by Mercedes-Benz, this model was a significant step forward compared to its predecessor, offering buyers not only an elegant design visually similar to the senior models in the lineup but also an extensive set of advanced technologies.

History and Facelift Features

The face lifted version of the Mercedes-Benz C-class W205 was presented at the Geneva Motor Show in 2018. The updated model was produced until 2021 when it was replaced by a new generation. The changes affected not only the exterior design of the car but also its technical components, making the vehicle even more refined and technologically advanced.

One of the key technical changes was the complete transition to the nine-speed automatic transmission 9G-Tronic. This transmission completely replaced the previously used seven-speed version, providing smoother gear shifts and improved fuel efficiency. In addition, a new inline gasoline engine, the M264, appeared in the engine lineup, becoming an important addition to the model range.

Body Styles and Configurations

The face lifted C-class was available in four body styles: sedan, wagon, coupe, and cabriolet. Notably, the cabriolet was supplied exclusively in all-wheel drive configuration, while the other body types were available with both rear-wheel and all-wheel drive. The transmission in all versions was exclusively automatic, with no manual version provided for this generation.

Gasoline Engine Lineup

The New M264 Engine

One of the main innovations of the facelift was the M264 engine, presented in two modifications. The M264 E15DE AL, a 1.5-liter unit, was installed in hybrid all-wheel-drive sedans, hybrid coupes, and cabriolets (only in the lower power version). The two-liter version, M264 DE20 AL, was used in rear-wheel-drive sedans and all-wheel-drive hybrid coupes.

The Time-Tested M274

The second main gasoline engine remained the well-known four-cylinder inline engine M274, which was used before the facelift. The junior modification M274 DE16 AL was installed in rear-wheel-drive sedans, wagons, and coupes, while the senior version M274 DE20 AL was intended exclusively for all-wheel-drive sedans.

Diesel Versions

OM654 Engine

With the brand's departure from some markets, unofficial imports of diesel versions began, among which the modification with a four-cylinder inline engine OM654 DE16 GSR with a displacement of 1.6 liters gained the most popularity.

Maintenance and Operation Features

Oil and Technical Fluids

The quality of engine oil plays a critically important role in the longevity of Mercedes-Benz C-class powertrains. Modern engines require the use of oils that strictly comply with the manufacturer's specifications. It is important to follow the recommended viscosity and approvals for the specific engine modification. When choosing oil, attention should be paid to compliance with Mercedes-Benz approvals, the presence of necessary additives, and the ability of the oil to quickly flow to all engine parts.

Fuel System

The 274 series gasoline engines are particularly demanding on fuel quality. For their trouble-free operation, it is necessary to use only high-quality fuel, regularly conduct preventive maintenance of the fuel system, and avoid operating the vehicle with a minimum fuel level in the tank.

Typical Problems and Solutions

M274 Gasoline Engine Problems

The most common problem with M274 engines is the premature failure of the crankcase ventilation valve. The average service life of this component is about 60-70 thousand kilometers. Warning signs of malfunction include:

• Inadequate response to the accelerator pedal
• Spontaneous changes in engine speed
• Loss of traction
• Appearance of an unpleasant odor in the cabin
• Error P052E71 on the instrument panel

Other characteristic problems of the M274 include jamming of the generator's overrunning clutch (usually after 80-90 thousand km), leaks of the front crankshaft seal, timing cover leaks, and oil pump valve error P06.

M264 Operation Features

The M264 series engines, being relatively new (production started in 2017), have not yet shown such an extensive list of typical malfunctions. However, some problem areas have already been identified, such as the crankshaft position sensor (problems arise at 30-40 thousand km) and a characteristic "kick" during rapid acceleration at speeds of 70-130 km/h.

OM654 Diesel Problems

The main weak points of the diesel unit are in the roller rocker arms with a resource of 130-150 thousand km, oil getting into the vacuum tubes, and malfunctions of the tandem oil pump check valve.

Transmission

9G-Tronic Automatic Transmission

The nine-speed automatic 9G-Tronic has generally proven itself to be a reliable unit. After working out the "childhood diseases" on heavier Mercedes-Benz models, it integrated almost perfectly into the C-class. For long and trouble-free operation, it is recommended to:

• Regularly change the transmission fluid every 40-50 thousand km
• Avoid an aggressive driving style in the first minutes after starting
• Systematically monitor the level and condition of the fluid

4Matic All-Wheel Drive System

The 4Matic all-wheel drive system works reliably, but requires attention to some components. The front drive rarely serves more than 100-120 thousand km, and the bearing of the intermediate shaft of the front axle may require replacement as early as 40 thousand km.

Suspension and Chassis

Design Features

The suspension of the facelifted W205 requires regular attention and maintenance. Despite the premium status of the car, some elements have a relatively short service life.

Typical Suspension Problems

Springs may crack by 100 thousand km and require paired replacement. The resource of hub bearings is 100-120 thousand km, they require timely diagnostics. The average resource of shock absorbers reaches 70-80 thousand km, although replacement may be necessary as early as 30-40 thousand km, and many owners are dissatisfied with the characteristics of the original shock absorbers. Front control arms are noted for the appearance of squeaks and knocks as early as 30 thousand km and require regular diagnostics and maintenance.

Electrical and Electronics

Common Problems

Seat heating often fails after 80-90 thousand km, the cause should be sought in the control unit under the seat. The wiper linkage is a mass problem after 80-90 thousand km due to wear of plastic joint connections.

Electronic Systems

The modern C-class is equipped with many electronic systems that require periodic diagnostics and software updates. These include the MBUX multimedia system, adaptive cruise control, active safety systems, and parking assistants.

Body and Paint

Paint Quality

The Mercedes-Benz C-class W205 is distinguished by high-quality paintwork. The body is well protected from corrosion thanks to quality galvanization, multi-layer coating, and protection of hidden cavities.

Vulnerable Areas

Despite the overall high quality, there are areas that require special attention: the lower edges of doors, wheel arches, and molding installation places.

Interior and Comfort

Material Quality

The interior of the facelifted C-class is executed at a high level using quality materials: soft plastic on the dashboard, leather trim (depending on configuration), aluminum or wooden decorative inserts.

Ergonomics and Functionality

The driver's workplace is thought out to the smallest detail: comfortable seating with multiple adjustments, intuitive system control, and quality sound insulation.

Safety Systems

Active Safety

The Mercedes-Benz C-class is equipped with a wide range of active safety systems, including collision prevention system, blind spot monitoring, lane keeping, and adaptive cruise control with Stop&Go function.

Passive Safety

The car provides a high level of passenger protection thanks to a strong body structure, multiple airbags, and seat belt pretensioners.

Recommendations for Selection and Operation

When purchasing, attention should be paid to:

• The service history (availability of a service book and documents on work performed)
• The reality of the indicated mileage
• Suspension condition (inspection on a lift is mandatory)
• Engine operation (absence of extraneous noises and vibrations)
• The smoothness of transmission gear shifts

Regular maintenance should include:

• Oil and filter changes according to the schedule
• Suspension condition monitoring
• Electronic systems diagnostics
• Brake system checks
• Transmission servicing

AMG Modifications

For speed enthusiasts, charged AMG versions with more powerful engines were offered: the three-liter M276 and four-liter M177. These modifications differ not only in more powerful engines but also in reinforced transmission, sports suspension, and aggressive exterior design.

Advantages and Disadvantages

The main advantages of the Mercedes-Benz C-class W205 include:

• Premium level of comfort
• Rich technical equipment
• Quality interior materials
• Good handling
• Reliable 9G-Tronic transmission
• Wide selection of engines

Among the disadvantages are:

• Relatively short service life of suspension elements
• Problems with the crankcase ventilation valve on the M274
• Expensive maintenance
• Demanding fuel quality requirements
• Complexity of self-repair

Conclusion

The Mercedes-Benz C-class W205 after the facelift represents a mature and technically perfect premium class car. Despite some typical problems characteristic of modern complex cars, with proper and timely maintenance, this model can provide the owner with comfortable and safe operation.

When choosing a used C-class W205, it is important to understand that this is a premium car that requires an appropriate approach to maintenance. Savings on technical maintenance can result in significant expenses in the future. With a competent approach to operation, the Mercedes-Benz C-class W205 will become a reliable companion, combining comfort, safety, and driving pleasure.

The model remains one of the best representatives of the premium D-segment, offering an optimal combination of size, comfort, technology, and the prestige of the Mercedes-Benz brand.

Find Your Mercedes C-Class W205

We've collected second-hand listings from Facebook Marketplace, Kaidee, One2Car, and TaladRod all in one place. Compare prices, check seller types, and find the perfect match for your needs.

Find second-hand Mercedes C-Class W205 in Thailand here → Mercedes C-Class W205 on Roddee PRO