2017 Mercedes-Benz A-Class 2.1L Diesel · OS55 ARA

A persistent theme in the MOT history of this 2017 Mercedes-Benz A-Class is the gradual and now well-established deterioration of the braking system, particularly at the front axle, alongside emerging concerns with emissions compliance. The vehicle passed its most recent test on 8 June 2026, but only after initially failing on the same date due to a malfunction indicated Engine Management Lamp, an inoperative front windscreen washer, and a nearside front headlamp aimed too low. The diagnostic trouble codes behind the engine MIL warning are not recorded in the MOT data and warrant direct investigation, as this emission-related flag can stem from issues ranging from a faulty sensor to catalytic converter efficiency problems. The latest test also carried advisories for a perished nearside rear tyre and pitted rear brake discs on both sides. When viewed across the full five-year record, the front brake discs have appeared as an advisory in every annual test since 2023, with the pad wear escalating to a wearing thin advisory in 2025, suggesting that the braking components are approaching a service interval replacement point. Against the backdrop of approximately nine years of service and a recorded mileage of 64,433 miles, the average annual accumulation of around 7,159 miles is broadly typical for a car of this age in the UK. The MOT entries show consistent year-on-year testing with no extended gaps, which suggests the vehicle has remained in regular road use rather than being laid up for prolonged periods. This continuity provides a fairly complete picture of the mechanical wear trajectory, though the steady creep of brake-related advisories and the recent engine management failure are the natural consequences of a higher-mileage urban-driven car where braking demand is high and stop-start cycles are frequent. For a prospective buyer, the most pressing area to scrutinise on a physical inspection is the braking performance and pedal feel, given the documented history. On a test drive, listen for any grinding, squealing, or pulsation through the pedal under firm application, which would indicate that the front discs, now pitted and worn across multiple tests, may have reached the minimum thickness or developed lipping that could compromise braking efficiency. The rear discs were noted as pitted and scored in the latest test, so uneven braking or pulling to one side under heavy deceleration could also be symptomatic of further rear disc wear or caliper binding. It would also be sensible to check the condition of the front brake pads directly, as the 2025 advisory confirmed they were wearing thin, and confirm whether a replacement has since been carried out. Beyond the braking system, the recent failure items demand careful verification. Confirm that the engine management light remains off under normal driving conditions and that no warning lamps illuminate on the dashboard during a cold start and warm-up cycle, as an intermittent sensor fault could easily return. Verify that both the front windscreen washer jets are functional and delivering fluid to the screen, and check the headlamp alignment visually by parking on level ground facing a wall to ensure both beams strike at the correct height and not into the foreground. The perished nearside rear tyre should be replaced prior to use regardless of remaining tread depth, as cracking of the sidewall rubber is an MOT failure point at the next test. Finally, given the recurring brake disc advisories across all four corners over consecutive years, obtaining a written quote for a full brake disc and pad refurbishment would be a prudent negotiation point before purchase.