2005 Mercedes S-Class 3.2L Diesel · PD05 PJD

The most recent DVSA MOT test on 12 August 2025 resulted in a pass with no defects or advisories recorded, which is the cleanest outcome in the available history and suggests that the vehicle is currently in a roadworthy condition at the point of test. However, reviewing the broader pattern reveals that this is a vehicle with a recurring background of advisories and at least two recent failures, so the latest clean pass should be viewed as a snapshot rather than an indicator of consistent mechanical refinement. The 2023 and 2024 tests both carried identical advisory notes concerning rear brake disc wear, rear tyre perishing, and a minor exhaust flexi joint leak, suggesting that while these items were not severe enough to fail, they represent a known pattern of deterioration that may have been recently addressed or may still be developing. The failure in July 2022 also flagged an upper anti-roll bar pin or bush issue at both sides and a shock absorber oil misting advisory, all of which sit within the suspension and chassis systems typical of an S-Class of this age and mileage. Overall, the trend is best characterised as one with known recurring wear points that have been managed rather than fully resolved, and a careful buyer should treat the clean 2025 result as positive but not definitive. The recorded mileage of 125,446 miles over approximately twenty-one years equates to an annual usage of around 5,974 miles, which is notably low for a vehicle of this vintage and substantially below the average for a Mercedes-Benz S-Class. This figure suggests either a long period of light use, significant standing time, or possibly periods of inactivity followed by limited use, all of which carry their own mechanical consequences. Low annual mileage typically results in extended oil change intervals becoming calendar-dependent rather than mileage-dependent, leading to degraded engine oil, reduced additive effectiveness, and potential sludge formation, as well as brake fluid that absorbs moisture over time and significantly reduces its boiling point. Equally, long periods of standing are notorious for promoting binding brake calipers, surface corrosion on brake discs, deterioration of flexible exhaust sections, and degradation of rubber components throughout the chassis and drivetrain. The recorded pattern of advisories and the prior failure history are consistent with a vehicle that has likely spent considerable time inactive, where standing-related corrosion and rubber perishing have gradually taken their toll. Given the recurring advisories on the rear brake discs and rear tyres over consecutive tests, a prospective buyer should pay particular attention to the condition of the rear braking system and the rear axle tyres during a physical inspection and test drive. Brake discs that have been repeatedly noted as pitted or scored suggest prolonged light use combined with infrequent braking, which allows surface corrosion to develop and embed into the disc face; on a test drive, listen for any scraping or grinding noise from the rear wheels during low-speed manoeuvres, and feel for any brake shudder or uneven retardation that would indicate excessive disc run-out or caliper slide pin seizure. The advisories on rear tyre perishing are particularly relevant for a 2005 vehicle, as tyres more than five to six years old are prone to sidewall cracking and dry rot regardless of tread depth; inspect both rear tyres closely for hairline cracks in the sidewall rubber, check the DOT date code to confirm age, and verify that any replacements are recent. The exhaust flexi joint leak noted in both 2023 and 2024 is also worth re-examining by listening for any ticking or escaping gas noise from the centre of the exhaust under load, and inspecting the flexible section for black soot staining or visible cracking. Beyond the advisories, the July 2022 failure items warrant specific attention, as anti-roll bar bushes and brake pipe corrosion are common age-related concerns on a low-mileage vehicle that has spent long periods standing outdoors. Upper anti-roll bar pin or bush wear at both sides within the same test points to general age-related hardening and deterioration of the polyurethane or rubber bushes, which on a test drive would manifest as a clonking or rattling noise from the front suspension over speed humps, uneven road surfaces, or during sharp direction changes, accompanied by a degree of vagueness or float in the front end response. The failed brake pipe and dangerous brake efficiency failure from 2020 indicates that corrosion within the braking hydraulic system was at one point a serious concern; although this will have been rectified to pass subsequent tests, the entire brake pipe network should be inspected for surface rust, particularly along the underbody and around the rear axle, and the brake fluid should be tested for moisture content, as fluid older than two years significantly compromises braking performance under repeated heavy use. Finally, given the extended standing periods suggested by the low mileage, the buyer should verify the age and condition of the 12V battery, confirm a comprehensive recent service history with documented replacement of brake fluid, coolant, transmission fluid, and engine oil at appropriate calendar intervals, and ensure that the air suspension components, a known long-term wear area on the S-Class, are functioning without warning messages or compressor overrun on cold starts.