2018 Mercedes-Benz A-Class 1.5L Diesel · AM68 NDA

A 2018 Mercedes-Benz A-Class with a broadly stable MOT trajectory is undermined by a cluster of three major defects recorded at the 2024 test, all of which would have rendered the car illegal to drive home at the time. These ranged from a malfunctioning Tyre Pressure Monitoring System and an illuminated Engine Management Indicator Lamp to front wiper blades that failed to clear the screen effectively, suggesting a period in which routine maintenance and dashboard fault investigation were deferred. The subsequent pass on 4 October 2025 with no advisories or defects is a positive indicator that these issues were addressed, but a single clean test following a failure-heavy event does not eliminate the possibility of intermittent faults returning, particularly given that the underlying causes of the TPMS and MIL warnings were not itemised in the test record itself. The earlier 2021 failure for a deeply cut offside front tyre, accompanied by advisories for all four worn brake discs and headlamp aim irregularities, points to a vehicle that may have experienced a lapse in attention to consumable items around that time, with the brake disc advisory in particular being a recurring consideration for any used A-Class of this age and mileage. Annual mileage of approximately 3,440 miles is substantially below the average for an eight-year-old vehicle, which raises a specific set of mechanical considerations rather than the usual wear concerns associated with higher-mileage examples. Prolonged standing periods, particularly if the car has been used predominantly for short trips or left idle for extended stretches, can accelerate degradation of components such as brake calipers, suspension bushes and the 12V battery due to lack of regular thermal cycling and corrosion protection from driving. The annual accumulation has remained broadly consistent, with tests conducted in consecutive years from 2021 onwards showing no large mileage jumps, which reduces the likelihood of heavy motorway use having worn the drivetrain disproportionately. For a prospective buyer, the priority items to investigate are the brake system, given the 2021 advisory noting wear on all four discs, and the headlamp aim concerns that were flagged on both sides of the front end at the same test. A physical inspection should establish whether the discs have been replaced or merely skimmed, and whether the caliper guide pins are free to move, as seized calipers are a common cause of uneven pad wear on Mercedes-Benz models of this era. On a road test, listen for any grinding or rubbing from the front end under light braking, check for pulling to one side which could indicate a binding caliper or uneven pad transfer, and feel for judder through the steering wheel or brake pedal that may suggest disc runout. The headlamp aim should be rechecked against a wall, as the recorded advisories of one lamp being at the highest acceptable level and the other at the lowest indicate that the adjustment mechanism or supporting structure may have shifted. The most recent 2025 pass with no recorded items is encouraging, but the timing and nature of the 2024 failures warrant further enquiry, particularly a diagnostic read of any stored fault codes relating to the tyre pressure monitoring system and engine management, as the MOT test only records the presence of a warning light rather than the underlying cause. The nearside rear tyre edge wear advisory from 2024, noted on both the failure and subsequent pass, may suggest an alignment issue that has not been rectified, so a four-wheel alignment check would be prudent, and an inspection of the rear suspension bushes and trailing arms for cracking or perishing is advisable given the vehicle's age. Finally, the plastic floor sill and engine cover advisory from 2021 is purely cosmetic and prevents visual inspection of certain structural and engine components, so any inspection should insist on the removal of these covers to allow proper assessment of corrosion and oil leaks from below, particularly around the subframe mounting points which are a known area of concern on the W176 A-Class platform.