2006 Mercedes-Benz S-Class 3.5L Petrol · CT06 MFF

The most recent MOT, carried out on 16 November 2025, was passed but recorded an advisory for an oil leak. Over the preceding six years the vehicle has moved from a series of dangerous and major failures in 2021 and 2023 to a pattern of passing tests with only advisory items in 2024 and 2025. Although the oil leak and occasional handbrake limit warning indicate that some components are reaching the end of their service life, the absence of any further dangerous failures suggests the overall maintenance trend is stabilising and modestly improving, provided the outstanding advisories are addressed promptly. With a recorded 105,043 miles on a 2006 S‑Class the average annual mileage works out at roughly 5,250 miles per year, which is well below the typical UK usage of 8‑12 000 miles. Such low utilisation often points to long periods of inactivity or occasional use, both of which can accelerate age‑related deterioration even while mechanical wear remains modest. The low mileage is favourable for engine wear and internal components, but the vehicle’s age means that rubber seals, suspension bushings, brake lines and electrical systems are likely to have suffered from calendar ageing and possible corrosion from standing. A prospective buyer should give particular attention to the front suspension and steering assemblies, as the MOT record shows repeated concerns with the off‑side front track‑rod end ball joint, the front lower suspension arm ball joint and the associated dust cover. On a test drive listen for clunking or knocking when traversing bumps or when steering through corners, and feel for any looseness or play in the steering wheel. Inspect the ball joint boots for cracks or leakage, verify that the dust covers are intact and free of dirt ingress, and check the condition of the under‑tray for corrosion that could affect the rear brake pipe, which has been noted as corroded and greased in previous tests. The oil leak advisory should be traced to its source – a common origin is a valve cover gasket or oil filter housing seal on this model – and any oil staining around the sump or under the vehicle should be examined. The handbrake limit warning and ABS fault lamp also merit investigation; ensure the handbrake engages firmly without excessive travel and confirm that the ABS warning light remains off after a brief road test, as intermittent faults can indicate failing wheel speed sensors or a deteriorating control module. Finally, verify that the windscreen washer system is no longer leaking and that the pump delivers adequate fluid, as previous major failures in this area can lead to reduced visibility in wet conditions. Given the vehicle’s two‑decade age, irrespective of mileage, the buyer should also conduct a thorough age‑related inspection. Examine all tyre sidewalls for cracking, dry rot or uneven wear, especially on the front tyres which previously fell below the legal tread depth. Check the brake discs for surface rust, scoring or glazing and confirm that the calipers move freely without binding. Inspect the battery for sulphation, low voltage and swollen cells, and consider a load test as batteries over twenty years old often lose capacity even with low usage. Review the service book for evidence of regular oil, coolant and brake fluid changes; fluids should be replaced at least every two to three years regardless of mileage to prevent seal degradation. Look for any signs of chassis rust, particularly around wheel arches, suspension mounting points and the under‑tray, and ensure that all rubber hoses, belts and grommets are supple and free of cracks. Addressing these points will give a clear picture of the car’s current roadworthiness and the likely cost of bringing it to a reliable, long‑term condition.