BMW M135i common MOT failures and failure rate
What a BMW M135i fails its MOT on, from real DVSA test data, and the part that resolves each item.
Based on 400 MOT tests in DVSA data.
About 7.2% of MOT tests recorded on the BMW M135i in DVSA data end in a failure. The same handful of items account for most of them.
Its most common failure is tyres, which makes up 10.3% of the BMW M135i's failures, followed by tyres, exhaust & emissions, lamps & electrical, visibility/wipers. Each item below links to the part that resolves it. Confirm the exact fitment against your registration or VIN before buying, and have safety-critical work done by a competent mechanic.
What it fails on, and why
Tyres fail for tread below the 1.6mm legal limit across the central three-quarters, uneven or exposed-cord wear, or sidewall damage. The tester inspects all four; a single illegal tyre is a fail.
Exhaust failures cover leaks, insecure mountings and emissions over the limit. A blowing exhaust, a failed lambda reading or a diesel that smokes beyond the limit will fail.
Lighting is the single most common MOT failure and the cheapest to put right. A blown headlight, brake-light or number-plate bulb, a cracked lens, or a headlamp beam that points too high or low will all fail. Most are a two-minute bulb swap.
Visibility failures include torn or smearing wiper blades, a washer jet that does not reach the screen, and chips or cracks in the driver's swept area. Blades and washer fluid are quick, cheap fixes.
The parts that fix each
If your car has just failed, you have 10 working days to fix the items and get a free partial retest. These are the usual parts; confirm the exact fitment against your registration or VIN before buying.
Other models
Sources: DVSA MOT History API: MOT test results and defect data ยท DVSA MOT testing data for Great Britain