2016 BMW 640 3.0L Diesel · MJ16 EAC

A persistent front-engine oil leak has emerged as the defining mechanical thread in this BMW 640's recent MOT history, appearing as an advisory on the two most recent tests in September 2025 and August 2026, while the rest of the record from 2020 through 2024 was entirely free of advisories. The vehicle has passed every test recorded in the DVSA history with no failures, and aside from that recurring oil seepage and two isolated tyre wear advisories, the tester observations point to a broadly stable roadworthiness profile. The fact that the leak has been flagged two years running but is described as not excessive suggests it has remained a slow seepage over that period rather than escalating, though any oil leak on a 6 Series demands attention because of the proximity of the engine bay to the exhaust manifold and the risk of oil tracking onto undertray or subframe components over time. With eight tests on file spanning 2020 to 2026, the mileage of 75,465 against a 2016 registration equates to roughly 7,500 miles per year on average, which is on the lower side for the age bracket and indicates usage consistent with mixed private and occasional longer journeys rather than daily commuting. The relatively even spread of annual mileage reduces the likelihood of significant driveline wear from high-mileage accumulation, but the lower annual figure also means the vehicle may have experienced periods of standing, which can bring their own concerns around brake disc corrosion, tyre flat-spotting, and stale rubber components in the cooling and fuel systems. There are no significant gaps between test dates, so the pattern points to continuous road use throughout the recording window. On inspection, particular attention should be paid to the underside of the engine and the oil filter housing area, which is a known seepage point on the N63 and related V8 units fitted to this generation of 6 Series, checking for fresh oil film on the sump, filter housing, and any residue tracking onto the exhaust downpipe. A test drive should include a cold start from cold to listen for any timing chain or valve train chatter, followed by a warm running period to observe for any rise in oil pressure warning behaviour or visible increase in oil mist around the engine bay. The 2025 advisory noted an offside front inner tyre worn close to the legal limit and on its edge, so pay close attention to steering response and tracking, particularly any pulling to one side or uneven shoulder wear on the front axle that might indicate a worn control arm bush or top mount rather than a simple alignment issue. Given the rear nearside tyre advisory from 2022 and the front tyre advisory from 2025, it would be prudent to inspect all four corners closely for uneven shoulder wear, sidewall cracking from age, and to confirm the fitted tyres are of matching brand, size, and load rating. Braking performance should be evaluated from both cold and after a few firm stops to check for any judder through the pedal, which on a 6 Series can point to warped front discs or a binding caliper, the latter a known concern on vehicles that see periods of light use. Finally, ask for documentation of any recent oil leak repair or sealant work, and verify the oil level on the dipstick is at maximum before any purchase, as a persistent seepage of two years standing can gradually consume oil between service intervals.