2009 BMW 635 3.0L Diesel · WF09 XER

The 2009 BMW 635 presents a mixed mechanical picture across its 17-year ownership history, characterised by intermittent failures rather than consistent degradation. The most recent MOT conducted on 2026-01-03 resulted in a passing result, though it carried a minor advisory regarding offside front outer suspension arm ball joint with slight play. This finding sits alongside a pattern of earlier issues including a nearside front lower suspension arm ball joint failure in June 2023, multiple brake-related advisories spanning 2020-2023, and a front brake pad thinning concern in 2023. The progression from a 2023 failure through two subsequent passes indicates a trajectory of stabilisation, with the current test reflecting improved compliance despite retained minor concerns that require verification. At 167,468 miles on its 17th anniversary, the vehicle accumulates approximately 9,850 miles annually, a rate that aligns with typical depreciation and practical usage for a model of this age. The testing record reveals a clear gap between the 2023-06-06 failure and the next MOT in August 2024, during which the car remained compliant with no further advisories recorded. Since that period, the absence of additional failures suggests the underlying issues have been managed, though the longer interval since the last failure warrants scrutiny of whether routine inspections were adequately performed throughout the intervening months. The steady accumulation pattern implies moderate daily or weekly usage rather than extreme mileage spikes, which would otherwise accelerate wear on critical components such as suspension bushings and brake systems. Focused attention should be directed at three primary systems flagged in the historical record. The front lower suspension arm ball joints represent the most immediate mechanical concern, with the 2026-01-03 advisory indicating slight play that could manifest as a clunking noise over bumps or subtle steering irregularities under load. A physical inspection of the ball joints and associated bushings is essential, particularly when the vehicle encounters uneven surfaces. Simultaneously, the documented oil leak from June 2023 requires confirmation of containment and source—leaks often originate from seals or hoses that may have deteriorated due to age, potentially leading to reduced engine performance or increased consumption. The front brake pads show continued thinning according to the 2023 assessment, and combined with the noted nearside front brake disc scoring and pitting, this suggests a gradual reduction in braking surface area that should be verified visually and measured against safety thresholds. Beyond the highlighted components, the rear tyres showing wear close to legal limits in both 2020 and 2019 indicates cumulative exposure to highway speeds or aggressive driving conditions, making regular visual checks and possibly rotation advisable prior to acquisition. Given the history of suspension arm failures and the presence of an oil leak, a thorough inspection of the subframe and surrounding suspension geometry is prudent, as rust or corrosion may have compounded the initial ball joint weaknesses. Before committing, request a detailed breakdown of the repair history for the suspension components and ask for photographic evidence of any rust or damage to the subframe, ensuring that the current state reflects genuine mechanical health rather than cosmetic appearance alone. These targeted checks will provide the necessary confidence to assess whether the vehicle remains roadworthy despite its extended service life.