2015 BMW 420 2.0L Diesel · RF65 WKX

A pattern of steering and rear tyre wear stands out as the defining mechanical theme of this 420, with the 2022 test failure on the windscreen washer providing the only outright defect on the record. Across seven tests spanning 2019 to late 2025, the vehicle has passed every examination, and the most recent assessment on 4 December 2025 recorded no defects at all. However, the underlying advisories tell a more nuanced story. The 2022 entry flagged play in the offside steering rack inner joint, a component that, if left unaddressed, can develop into a more serious rack or tie-rod concern. The 2023 test then noted both rear tyres worn close to the legal limit on their edges, a wear pattern often associated with rear suspension geometry or alignment issues rather than simple age-related tread loss. With two consecutive clean passes since then, the recent trend is stable, but the recurring nature of steering and tyre wear advisories over a relatively short window warrants close inspection. At 169,199 miles against an 11-year life, this 420 is running at roughly 15,382 miles per year, a notably high annual accumulation for a vehicle of this class. The mileage has progressed steadily through each test, with no gaps or periods off the road visible in the MOT record, which suggests the car has been in continuous, fairly intensive use. The 2020 advisories on 2mm rear brake pads and a worn rear tyre fit naturally with this usage profile, as high-mileage cars typically consume rear braking components and tyres at a faster rate than lower-mileage examples. Mechanically, this means consumables such as brake discs, pads, suspension bushes, and drivetrain mounts are likely to be approaching or already past their second or third lifecycle, and the buyer should anticipate proportionate wear on items not directly visible during an MOT. Given the steering rack inner joint flagged in 2022, a prospective buyer should specifically check for any remaining play or looseness in the steering by turning the wheel lock to lock with the engine running while stationary, listening for clunks or feeling for notching through the rack travel. It is also worth checking for uneven rear tyre wear on a physical inspection, as the 2023 advisories on both rear 225/50 R17 tyres suggest a possible camber or alignment issue that may not have been corrected. Any pulling to one side, vague steering response, or knocking from the front suspension over uneven surfaces would be immediate red flags. The TPMS warning light noted in 2023 is a relatively minor electrical concern but worth confirming is no longer illuminated, as it may indicate a faulty sensor rather than a simple reset requirement. On the test drive, attention should focus on brake feel given the 2020 advisory on rear pads wearing thin at 2mm. By now, those pads will almost certainly have been renewed, but the corresponding rear discs should be checked for lipping, scoring, or corrosion, as high-mileage 4 Series vehicles are prone to binding rear calipers which accelerate disc wear. Listen for any clonking or knocking from the rear suspension over speed humps and rougher tarmac, as continuous high-mileage use places considerable stress on trailing arm bushes and coil springs, neither of which have been flagged but are common wear items at this mileage. Finally, verify that the windscreen washer system is fully functional, as its failure caused the only MOT fail on the record, and confirm there are no dashboard warning lights present at start-up, particularly the tyre pressure monitoring system which has previously illuminated.