2017 BMW 420 2.0L Diesel · PB07 ROB

The most recent DVSA examination on 5 March 2026 returned a PASS, although an advisory remained outstanding for a deteriorated offside rear bump stop. This advisory has been carried forward consistently across every recorded test since at least February 2023, indicating it has not deteriorated into a failure point but has likewise never been rectified. The broader maintenance trend is stable rather than worsening, in that no further structural or safety-related failures have emerged beyond the single dangerous defect recorded in February 2026 and a pair of dangerous tyre and washer fluid issues in earlier years, all of which were remedied to allow subsequent passes. Nevertheless, the recurrence of the same advisory for four consecutive years suggests a degree of deferred maintenance, and a prospective buyer should treat the bump stop as a known item requiring attention rather than a fresh discovery. With 98,649 miles recorded over approximately nine years, the vehicle is averaging around 10,961 miles annually, which sits comfortably within the typical usage bracket for a car of this age and reflects steady, consistent driving rather than extended periods of standing or exceptionally high motorway accumulation. This mileage profile is broadly sympathetic to mechanical wear, meaning major drivetrain components such as the engine, automatic transmission and turbocharger are likely to have been worked sufficiently to remain healthy, while consumable items such as brake discs, pads, tyres and suspension components will have undergone normal progressive wear. There are no notable gaps in the MOT record that would suggest the vehicle was off-road for prolonged spells, so concerns regarding seized calipers, perished tyres from standing, or severely degraded brake discs through lack of use are less applicable here. The mileage is high enough, however, to warrant scrutiny of the timing chain, oil consumption habits and any evidence of timing chain stretching which is a known concern on certain BMW petrol and diesel engines of this era. A recurring item across the MOT history is the deteriorated offside rear bump stop, which is the rubber or polyurethane buffer that prevents the suspension from metal-to-metal contact at full compression. Continued deterioration will eventually lead to harsher impact loading on the rear coil spring and damper, potential knocking or clonking noises over bumps at the rear axle, and accelerated wear of the spring seat and surrounding components. On a test drive, listen for any rear suspension thud or metallic contact noise when travelling over speed humps or sharp undulations, and inspect the offside rear arch area for the bump stop visibly crumbling, splitting or missing entirely. Given the advisory has persisted since at least 2023, replacement is now overdue and represents a modest but worthwhile rectification costing a relatively small sum at any competent independent garage. Additionally, while not currently flagged, the front brake discs and pads on a 2017 BMW 4 Series at this mileage are approaching or due for renewal, and the rear tyres should be examined for age-related perishing on the sidewalls in addition to tread depth, particularly as previous front tyres have shown inner-edge wear which can point to tracking or suspension geometry misalignment. Beyond the recorded defects, a buyer should carry out age- and mileage-appropriate physical checks regardless of the MOT outcome. The 12V battery in a vehicle of this vintage will be approaching the end of its typical service life and should be load tested, as a weak battery can cause a cascade of electrical faults on modern BMW vehicles. Brake fluid should be considered due for renewal on a calendar basis given the age of the car, as moisture absorption reduces its boiling point and can compromise braking performance under heavy use, while the coolant and automatic transmission fluid will also benefit from sampling to check for degradation or contamination. Inspect the underside of the vehicle, particularly the rear subframe, diff mount, and exhaust mounting rubbers, for any corrosion or cracking consistent with the mileage. Finally, verify that the digital service history is up to date, confirm the iDrive system operates without warning messages, and ensure there are no stored drivetrain fault codes, as BMWs of this generation frequently develop sensor and emissions-related issues that do not always manifest at MOT time but can prove costly if ignored.