1986 BMW 635 3.4L Petrol · C21 UNV

The vehicle most recently passed its MOT on 21 May 2025, though the appearance of structural advisories suggests a declining trend in chassis condition. While the 2023 test was entirely clean, the latest inspection identified corrosion on both the nearside and offside rear sills within 30cm of a mounting point. Although these defects were not deemed serious enough to cause a failure at the time, they signal the onset of structural degradation in critical areas of the vehicle frame that will require monitoring and eventual remediation. With a recorded mileage of 155,849 miles over a forty year lifespan, the vehicle has averaged approximately 3,896 miles per year. This is considerably low for its age, indicating a history of light usage or extended periods of inactivity. While this low annual mileage likely preserves the internal mechanical components of the engine and gearbox, it often introduces a different set of risks associated with stagnation, such as the drying out of rubber seals and the accumulation of moisture in the braking system. A prospective buyer must prioritise a physical inspection of the rear chassis. The advisories regarding the inner to outer sills are particularly concerning on a vehicle of this era, as corrosion in these areas can quickly compromise structural integrity. Use a torch and a probe to check for soft spots or excessive flaking beneath the paintwork. During a test drive, listen for any unusual groans or clunks from the rear suspension, as corroded mounting points can lead to instability or premature wear of the suspension bushes. Given the low usage profile, it is essential to inspect all rubber components for perishing. Check the tyre sidewalls for fine cracking and verify the age of the rubber, as tyres can become unsafe due to age even if the tread remains deep. Inspect the brake discs for heavy surface corrosion and ensure the calipers are not binding, which is common in cars that stand for long periods. Finally, verify the service history to ensure that fluids have been changed based on a calendar interval rather than mileage, as oil and coolant degrade over time regardless of distance travelled.