2018 Mercedes-Benz C 2.1L Diesel · GL18 BWN

A concerning aspect of this Mercedes-Benz C-Class's MOT history is the simultaneous advisory and failure recorded on the same inspection date in April 2022, which points to a pattern of deferred rear tyre and brake maintenance. The vehicle failed its MOT due to brake pads worn down to the wear indicator at the rear and a front registration plate that did not conform to specified requirements, while the same inspection noted that both rear tyres were worn close to the legal limit and worn on the edge. Edge wear on the rear axle is a notable mechanical indicator on a rear-wheel-drive chassis of this era, as it can suggest either persistent misalignment of the rear suspension geometry or sustained cornering loads that have compromised the tyres before their expected service interval. The cluster of braking and tyre wear items recorded together suggests the rear axle braking and suspension components warrant close scrutiny before purchase, particularly given the failure represented an immediate roadworthiness issue at the time of test. Recorded mileage of 45,972 miles across eight years equates to an average annual accumulation of roughly 5,746 miles, which is below typical for a vehicle of this age and class. This lower-than-average usage profile has direct mechanical implications: the brake pads reaching the wear indicator despite modest annual mileage could point to a binding rear caliper or seized slider mechanism rather than purely friction-based wear, and the rear tyre edge wear may be exacerbated by geometry that has shifted during periods of stationary storage. Under trays and engine covers were also noted as fitted at the time of inspection, which restricts visual access to the underside of the vehicle and means several common Mercedes-Benz advisories relating to oil leaks, underbody corrosion, and component condition may not have been recorded. The combination of low mileage and covered underbody introduces uncertainty around the condition of oil seals, the subframe mounting points, and the exhaust system, all of which can deteriorate during lay-up periods even if total mileage remains low. Given the recorded rear brake and tyre wear pattern, particular attention should be paid to the rear caliper carriers, slide pins, and handbrake mechanism during a pre-purchase inspection. A binding caliper will typically present as a dragging sensation, uneven pad wear across the rear axle, or a hot rear wheel hub after driving, and the handbrake may feel inconsistent or require excessive lever travel if the internal mechanism has seized. On a test drive, listen for any clonking or knocking from the rear suspension over uneven surfaces, as the multi-link rear arrangement common to this model is susceptible to wear in the control arm bushes and trailing arm bearings, particularly on vehicles that have stood for extended periods. Steering pull, vibration through the pedal under braking, or a noticeable judder would also warrant investigation, as these symptoms often accompany worn rear brake components or compromised rear tyre sidewalls. The reported tyre edge wear pattern strongly suggests a four-wheel geometry check should be commissioned regardless of any current steering complaint, with particular focus on the rear camber and toe settings, as out-of-specification rear geometry on this chassis will continue to chew through tyres prematurely even after a fresh set is fitted. Beneath the engine and transmission covers, request that the inspecting technician specifically check for oil misting around the OM654 diesel or M274 petrol engine's cam cover and oil filter housing, both common seepage points, and inspect the front subframe and rear axle carrier mounting points for any surface corrosion, which is a known advisory area on C-Class vehicles approaching a decade of service. Confirm that the registration plate compliance issue noted at the 2022 test has been resolved with a correctly spaced and font-conforming plate, as this is a straightforward but commonly overlooked rectification. Finally, verify the service history interval consistency, as the low annual mileage may have resulted in extended oil change intervals that increase the risk of internal engine deposits, particularly on a turbocharged unit of this generation.