2007 BMW Z4 2.0L Petrol · WN07 FHH

Chronic brake line corrosion is the defining mechanical theme of this 2007 BMW Z4, surfacing only at the most recent test on 6 January 2026 but doing so across four separate locations on the vehicle. All four brake pipe runs, nearside and offside rear, and the nearside and offside front-to-rear lines, were flagged as corroded and coated in grease or other material under the standard 1.1.11 (c) advisory category. The presence of grease coating is a common stop-gap measure used to slow surface corrosion on steel brake lines, suggesting the issue has been present long enough for someone to treat it cosmetically before the latest assessment. Prior to this, the MOT history was largely unblemished, with three consecutive clean passes in 2023, 2024, and 2025 and no recorded advisories, making the 2026 cluster of brake line flags a notable late-stage development rather than a long-running pattern. However, advisories on brake pipes are widely regarded as precursors to failure, and corrosion that has visibly developed on multiple lines simultaneously typically indicates systemic deterioration of the braking hydraulic circuit rather than an isolated cosmetic issue. The recorded odometer reading of 113,632 miles across approximately 19 years equates to an average accumulation of around 5,980 miles annually, which is low for a car of this age and platform. This level of use is more consistent with occasional weekend or fair-weather driving than with regular commuter mileage, and it implies that suspension, drivetrain, and braking components have experienced relatively modest wear in terms of total cycles. Conversely, low annual mileage on a Z4 often points to extended periods of standing, which carries its own mechanical considerations including potential for moisture ingress into brake hydraulic systems, drying and cracking of rubber components, and surface corrosion on underbody steelwork. The MOT history itself shows consistent annual testing with no significant gaps, so there is no evidence of an extended off-road period in the DVSA records, though the mileage trajectory still suggests the vehicle has spent long intervals inactive between annual tests. Buyers should be mindful that low mileage in this context is not automatically a positive indicator for a nineteen-year-old sporting convertible. The 2021 fail at an MoT bay on 5 January 2021 recorded two major defects, both for excessively worn inner rear bushes on the front lower suspension arms on the nearside and offside sides, which were then resolved for the pass recorded just two days later on 7 January 2021. Suspension arm inner bushes are a known wear item on E85 and E86 generation Z4s, and replacement of these components on both sides simultaneously suggests the wear was uniform rather than impact-related, consistent with the vehicle's age and rubber component degradation over time. Given that this repair was carried out five years ago, the buyer should reasonably expect the replacement bushes to be approaching the end of their typical service life again, particularly if the car has been stored for prolonged periods where rubber components can deteriorate through flexing under load without regular movement. On a test drive, listen for clonking or knocking noises from the front end over speed humps, uneven road surfaces, and during slow-speed direction changes, and feel for vagueness or delay in initial steering response which can indicate worn suspension linkages. The brake line corrosion flagged in January 2026 demands immediate and direct physical inspection, as grease-coated brake pipes can mask significant wall-thickness loss underneath. Any prospective buyer should arrange for the vehicle to be placed on a ramp so that all four brake lines can be visually examined for pitting, flaking, or rust scaling, particularly along the front-to-rear runs where road salt and moisture collect. Under braking, the pedal feel should be firm and progressive with no sponginess, excessive travel, or pulling to either side, and there should be no warning lights illuminated on the dashboard relating to the braking system. Beyond the recorded items, this age of Z4 is also prone to convertible roof mechanism wear, rear wheel bearing noise, and coolant leaks from the plastic expansion tank and water pump area, none of which are visible in the MOT data but which warrant a targeted physical inspection on a pre-purchase inspection lift. The combination of systemic brake pipe corrosion flagged at the latest test, the known suspension bush failure history, and the low annual mileage standing profile means this vehicle should be regarded as requiring thorough specialist inspection before commitment rather than as a turn-key purchase based on its generally clean recent pass record.