Air suspension (Airmatic)
usually 100,000–200,000 km · Medium risk
Signs: Car sits low, compressor runs long
Fix: Replace strut / compressor
€700–2,200
Common faults, service intervals and costs
Mercedes-Benz CLS (C257)
2018–2023
3
engines covered
4
known faults
2,634
roadworthiness tests in the statistics
Enter your VIN and mileage and get a plan built for your exact engine and gearbox.
The Mercedes-Benz CLS (C257) was built from 2018 to 2023.
For this generation we cover 3 engines and 4 known faults, each with the mileage range where it usually appears.
The most expensive known risk is Air suspension (Airmatic): it usually appears at 100,000–200,000 km and costs €700–2,200 to fix.
In UK roadworthiness tests in 2024, at 50–100 thousand km this model most often failed on: tyres and wheels (12.8 %), suspension (2.8 %), lights, wipers and visibility (1.8 %). It fails more often than an average car of the same age and mileage on: suspension, tyres and wheels, exhaust, emissions and leaks. It fails less often than average on: brakes, lights, wipers and visibility.
Engines
| Engine | Fuel | Timing drive | Oil |
|---|---|---|---|
| 2.9 d inline-six (Mercedes OM656) | Diesel | Chain | 0W-30 / 5W-30 · MB 229.52 / 229.71 · ~7.5–8.5 L · every 15,000 km |
| 2.0 d (Mercedes OM654) | Diesel | Chain | 0W-20 / 5W-30 · MB 229.52 / 229.71 · ~6.5 L · every 15,000 km |
| 1.5 / 2.0 petrol (Mercedes M260 / M264) | Petrol | Chain | 0W-20 / 5W-30 · MB 229.71 / 229.5 · ~6.5 L · every 15,000 km |
Faults typical of this model
Faults by engine
2.9 d inline-six (Mercedes OM656)
No typical faults on record.
2.0 d (Mercedes OM654)
AdBlue / SCR faults
usually 100,000–180,000 km · Medium risk
Signs: AdBlue warning
Fix: Replace NOx sensor or doser
€300–1,000
1.5 / 2.0 petrol (Mercedes M260 / M264)
48V belt starter-generator
usually 60,000–160,000 km · Medium risk
Signs: Start-stop faults, 48V warning
Fix: Replace RSG unit
€700–1,500
Gearboxes
5G / 7G / 9G-Tronic
Conductor plate / speed sensor (5G / 7G-Tronic)
usually 100,000–220,000 km · Medium risk
Signs: Stuck in gear, limp mode, harsh shifts
Fix: Replace the conductor plate; fluid every 60–100,000 km
€500–1,500
Scheduled service
Intervals and typical prices for the 2.9 d inline-six (Mercedes OM656) engine. Other engines differ in oil, timing drive and some filters; the app gives the exact plan.
| Item | Interval | Typical price |
|---|---|---|
| DPF health check (soot / ash load)Emissions | every 20,000 km | €0–60 |
| Engine oil + oil filterEngine | every 15,000 km or every 12 months | €70–150 |
| Cabin (pollen) filterClimate | every 15,000 km or every 12 months | €15–40 |
| Brake fluidBrakes | every 24 months | €50–95 |
| A/C service (regas + desiccant)Climate | every 24 months | €70–150 |
| Air filterEngine | every 30,000 km or every 24 months | €15–45 |
| Fuel filterFuel | every 30,000 km or every 24 months | €40–110 |
| Automatic transmission fluidTransmission | every 90,000 km | €200–450 |
| Glow plugsEngine | every 100,000 km | €120–300 |
| Auxiliary (serpentine) beltEngine | every 120,000 km | €70–180 |
| Coolant replacementCooling | every 150,000 km or every 96 months | €70–150 |
| Timing chain inspection (listen on cold start)Engine | every 150,000 km | €0–120 |
| Front brake padsBrakes | usually at 30,000–60,000 km | €60–150 |
| Front brake discs + padsBrakes | usually at 60,000–120,000 km | €150–320 |
| Rear brake padsBrakes | usually at 50,000–90,000 km | €50–130 |
| Tyres (set of 4)Wheels | usually at 40,000–60,000 km | €320–700 |
| Wiper bladesBody | checked at service | €20–50 |
| 12V batteryElectrical | checked at service | €100–220 |
Roadworthiness tests by mileage
Share of tests in the United Kingdom (DVSA MOT, 2024) that this model failed because of each system. Bold red means more often and green less often than an average car of the same age and mileage. Sample: 2,634 tests.
| thousand km | 0–50 | 50–100 |
|---|---|---|
| Brakes | 0.4 % | 1.2 % |
| Suspension | 0.9 % | 2.8 % |
| Steering | 0.0 % | 0.1 % |
| Tyres and wheels | 14.0 % | 12.8 % |
| Lights, wipers and visibility | 1.1 % | 1.8 % |
| Body and corrosion | 0.1 % | 0.6 % |
| Exhaust, emissions and leaks | 0.6 % | 1.4 % |
Most common engine versions in the EU
New cars of this generation registered in the EU, Iceland and Norway 2010–2025: 14,795, of which 19 in Croatia. The share shows how common each version is.
| Version | Share | Years | CO₂ | Fuel use |
|---|---|---|---|---|
| 2.9 d inline-six (Mercedes OM656)2.9 (2,925 cm³) · 210 kW (286 hp) · Diesel | 14.9 % | 2019–2021 | 189 g/km | 6.7 L |
| 3.0 Hybrid3.0 (2,999 cm³) · 270 kW (367 hp) · Hybrid | 14.5 % | 2019–2023 | 201 g/km | 8.9 L |
| 2.9 d inline-six (Mercedes OM656)2.9 (2,925 cm³) · 250 kW (340 hp) · Diesel | 14.1 % | 2019–2021 | 192 g/km | 7.0 L |
| 2.0 d (Mercedes OM654)2.0 (1,950 cm³) · 180 kW (245 hp) · Diesel | 11.2 % | 2019–2021 | 172 g/km | 6.5 L |
| 2.9 d inline-six (Mercedes OM656)2.9 (2,925 cm³) · 243 kW (330 hp) · Diesel | 10.7 % | 2020–2023 | 188 g/km | 7.2 L |
| 2.0 d (Mercedes OM654)2.0 (1,950 cm³) · 143 kW (194 hp) · Diesel | 8.1 % | 2019–2023 | 158 g/km | 5.9 L |
| 2.9 d inline-six (Mercedes OM656)2.9 (2,925 cm³) · Diesel | 7.0 % | 2019–2019 | 191 g/km | — |
| 3.0 Petrol3.0 (2,999 cm³) · 270 kW (367 hp) · Petrol | 6.3 % | 2019–2023 | 200 g/km | — |
| 1.5 / 2.0 petrol (Mercedes M260 / M264)2.0 (1,993 cm³) · 195 kW (265 hp) · Hybrid | 5.5 % | 2020–2023 | 162 g/km | 6.2 L |
| 1.5 / 2.0 petrol (Mercedes M260 / M264)2.0 (1,991 cm³) · 220 kW (299 hp) · Hybrid | 3.6 % | 2019–2023 | 188 g/km | 8.1 L |
Source: European Environment Agency (EEA), monitoring of CO₂ emissions from new passenger cars, CC BY 4.0. CO₂ and fuel use are official type-approval values (WLTP from 2021), not real-world consumption.
Common questions
Does the Mercedes-Benz CLS (C257) have a timing chain or a timing belt?
2.9 d inline-six (Mercedes OM656): chain; 2.0 d (Mercedes OM654): chain; 1.5 / 2.0 petrol (Mercedes M260 / M264): chain.
What are the known problems with the Mercedes-Benz CLS (C257)?
The faults with the highest risk: air suspension (Airmatic) (100,000–200,000 km, €700–2,200); 48V belt starter-generator (60,000–160,000 km, €700–1,500); conductor plate / speed sensor (5G / 7G-Tronic) (100,000–220,000 km, €500–1,500); adBlue / SCR faults (100,000–180,000 km, €300–1,000). The full list by engine is on this page.
What does the Mercedes-Benz CLS (C257) most often fail its roadworthiness test on?
In UK roadworthiness tests in 2024, at 50–100 thousand km this model most often failed on: tyres and wheels (12.8 %), suspension (2.8 %), lights, wipers and visibility (1.8 %). It fails more often than an average car of the same age and mileage on: suspension, tyres and wheels, exhaust, emissions and leaks. It fails less often than average on: brakes, lights, wipers and visibility.
What should you check when buying a used Mercedes-Benz CLS (C257)?
Before you buy, ask an authorised dealer to check by VIN whether the car has any open recalls. On the test drive, watch for these signs: car sits low, compressor runs long; start-stop faults, 48V warning. The full checklist is in the guide to buying a used car.
Other generations
Mercedes-Benz CLS (C219) 2004–2010Mercedes-Benz CLS (C218) 2011–2018
Models with the same engines
These models share engines with this car, so they share some of its faults too.
Mercedes-Benz C-Class (W205) 2014–2021Mercedes-Benz E-Class (W213) 2016–2023Mercedes-Benz A-Class (W177) 2018–Mercedes-Benz GLC (X253) 2015–2022Mercedes-Benz CLA (C118) 2019–Mercedes-Benz GLE (V167) 2019–Mercedes-Benz C-Class (W206) 2021–Mercedes-Benz GLC (X254) 2022–
Other Mercedes-Benz models
Mercedes-Benz B-Class (W247) 2018–Mercedes-Benz Sprinter (907 / 910) 2018–Mercedes-Benz EQC (N293) 2019–2024Mercedes-Benz GLB (X247) 2019–Mercedes-Benz GLS (X167) 2019–Mercedes-Benz X-Class 2017–2020Mercedes-Benz GLA (H247) 2020–Mercedes-Benz S-Class (W223) 2020–Mercedes-Benz Citan (W420) 2021–Mercedes-Benz EQA (H243) 2021–
Sources and notes
Faults, intervals and prices are indicative and collected from public sources and owner experience; always rely on the service book and a qualified workshop. Test statistics: DVSA – Anonymised MOT tests and results, Open Government Licence v3.0. Dutch tests: RDW Open Data (CC0). Engine versions: EEA, monitoring of CO₂ emissions from new passenger cars (CC BY 4.0, DG CLIMA). Owner complaints: NHTSA ODI (public domain). Recalls: DVSA Vehicle Safety Branch Recalls Database, OGL v3.0. Brand and model names are trademarks of their owners and are used only to describe the vehicles.
Updated 08/10/2026