1987 Mercedes 300 3.0L Petrol · E502 CVM

A 1987 Mercedes 300 with this MOT profile presents a broadly stable roadworthiness narrative, though the failure on 2025-03-06 for excessive exhaust emissions (8.2.2.2 (a)) and the subsequent clean passes on 2025-06-05 and 2026-06-12 indicate that the underlying cause was identified and rectified. A single emissions-related failure of this nature is not uncommon on a vehicle approaching its fortieth year, particularly if the engine management or fuel system had drifted out of specification. The absence of any advisories on the two post-repair passes is encouraging and suggests the remedial work held, although emissions-related issues on older Mercedes petrol engines can recur if root-cause components such as the lambda sensor, catalytic converter efficiency, ignition timing, or fuel metering were only partially addressed. The overall trend is therefore one of a brief lapse followed by restored compliance, which is preferable to a pattern of recurring or escalating defects. The recorded mileage of 77,094 miles across approximately 39 years equates to an average annual accumulation of around 1,977 miles, which is markedly low for any road vehicle and certainly for a classic Mercedes of this era. Such restrained usage typically reflects either occasional leisure use, long periods of storage, or a combination of both, and it carries mixed mechanical implications. Lower annual mileage reduces wear on major drivetrain components such as the engine, transmission, and final drive, but it simultaneously accelerates the degradation of rubber and polymer items that suffer from age-related perishing rather than mileage-related wear. On a 300 of this vintage, particular attention should be paid to coolant hoses, fuel lines, brake hoses, suspension bushes, drive shaft flexis, and various seals and gaskets that can harden and crack after extended periods of inactivity. The MOT record does not flag any testing gaps implying a long-term off-road lay-up, but the very low annual mileage still warrants close physical inspection of these age-sensitive components. Given the emissions failure on record, a prospective buyer should prioritise a thorough evaluation of the engine's running condition, both from cold and at operating temperature. Listen for any irregular idling, misfires, or hesitation under load, and observe whether the exhaust plume is visibly excessive or atypical in colour. On the test drive, pay particular attention to the behaviour of the braking system, as age-related perishing of brake hoses and seals is common on vehicles of this profile even when not yet flagged at test time. The pedal should feel firm and progressive without excessive travel or sponginess, and the vehicle should pull up straight without any indication of binding calipers or warped brake discs. Steering should be precise and free from excess play, as worn suspension linkages and bushes are a frequent source of advisories on older Mercedes saloons. Further inspection should concentrate on the underbody and structural condition, where corrosion can develop on sills, subframe mountings, suspension turrets, and brake and fuel pipework, particularly given the car's age. Examine the exhaust system for any signs of corrosion or blowing joints, as emissions issues can sometimes be traced back to air leaks upstream of the lambda sensor. The suspension should be tested over uneven surfaces for any clonks, knocks, or creaks that might indicate worn bushes or top mount deterioration, and the body should be checked for any rust bubbling around wheel arches, door bottoms, and the boot lid. Finally, verify that the emissions remedial work carried out after the March 2025 failure was documented and completed thoroughly, and confirm the current exhaust gas readings remain within manufacturer limits to ensure the rectification remains effective.