2012 Mercedes-Benz C 2.1L Diesel · SS53 STS

The most recent MOT test on 2026-06-30 resulted in a passing outcome, but this follows a pattern of recurring issues that have persisted over the past four years. While the vehicle has not failed an MOT since 2024-06-19, the history reveals persistent major and dangerous defects, particularly related to the engine control system (MIL) and tyre tread depth, alongside multiple advisories concerning brake system integrity, suspension wear, and corrosion. The fact that the vehicle has not been retested for major failures since 2025-06-12 suggests either ongoing unresolved issues or a pattern of deferred maintenance, which raises concerns about long-term reliability and roadworthiness. The presence of repeated advisories—such as worn suspension components and corroded brake pipes—indicates that the vehicle has not been fully serviced to address fundamental wear and tear, potentially leading to more critical failures if left unaddressed. The recorded mileage of 91,391 miles for a vehicle aged approximately 14 years represents a moderate annual usage rate of around 6,528 miles per year, which is within the expected range for this class of car. However, the lack of significant mileage spikes or prolonged periods of low usage suggests consistent, albeit not necessarily high-intensity, driving conditions. This profile does not inherently justify overlooking wear-related advisories, as even moderate mileage over time accelerates component degradation, particularly in the suspension, braking systems, and exhaust components. The absence of substantial mileage gaps could also imply that the vehicle has been in regular use, potentially leading to more rapid consumption of consumables like brake pads and suspension bushings, which are already flagged in the MOT history. For a prospective buyer, the most critical immediate actions should focus on the engine control system (MIL) issue, which has been a major failure point in two consecutive MOTs. The engine management system must be diagnosed and repaired to prevent further emissions-related failures and potential drivability issues. The nearside and offside rear tyres failing the 1.6mm tread depth requirement are dangerous defects that must be rectified immediately, as under-tread tyres are illegal and pose significant road safety risks. The advisories regarding corroded brake pipes and worn suspension bushings warrant thorough inspection—corroded brake pipes could lead to leaks or brake failure, while excessive suspension wear may result in handling instability or premature suspension failure. Beyond the MOT findings, a comprehensive pre-purchase inspection is strongly advised. Check the tyre sidewalls for signs of perishing or cracking, which can indicate age-related degradation despite the legal tread depth. Inspect the 12V battery for signs of corrosion, swelling, or poor connections, as a 14-year-old vehicle may have degraded battery health. Verify that all fluids—particularly brake fluid, coolant, and transmission fluid—are at the correct levels and show no signs of contamination or degradation, as these can deteriorate over time even without significant mileage. Ensure that the service book is up to date, particularly for timing belt replacement (if applicable), oil changes, and brake system servicing, as these intervals are critical for long-term reliability. Finally, conduct a test drive to listen for unusual noises—such as clunks from suspension components, uneven tyre wear patterns, or brake shudder—which could indicate deeper mechanical issues not flagged in the MOT. If the engine MIL persists, consider a professional diagnostic test to identify the exact fault code and scope of repair required.