Used car guide

2021 BMW 318I: common problems and what to check

What gets flagged at MOT on 2021 BMW 318Is, from 1,463 tests in 2025, plus known faults and what to look at before you buy one.

1,463MOT tests in 2025
88%pass first time (all 2021 cars: 87%)
10,500typical miles a year
1.9×the usual rate for brake pads

What stands out

Parts flagged at MOT more often on 2021 BMW 318Is than on all cars registered in 2021.

  • Brake pads1.9× usual
    BMW 318I
    12.8% All 2021 cars
    6.8%

    Failed outright at MOT: 1.9%, against 1.2% of all 2021 cars. The rest were advisories or minor defects.

    Rough price £75–£175 (one axle) ClickMechanic

    At the viewing: Listen for squealing or grinding when braking, and look through the wheel at how much pad is left.

By area

The share of 2021 BMW 318I MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Tyres
    28% of testsRough price £70–£150

    At the viewing: Check the tread on all four tyres, including the inside edges, and look for cracks or bulges.

  • Brakes
    15% of testsRough price £150–£350

    At the viewing: Look for a lip on the disc edges and feel for judder or pulling when braking firmly from about 40mph.

  • Wipers, windscreen and mirrors
    4% of testsRough price £15–£250

    At the viewing: Check for chips in the driver's view, and test the wipers and washers.

  • Suspension
    3% of testsRough price £120–£400

    At the viewing: Listen for knocks over speed bumps, and look behind each front wheel for a snapped coil spring.

  • Seats and seatbelts
    3% of testsRough price £80–£250

    At the viewing: Pull each seatbelt sharply. It should lock, and retract cleanly.

  • Lights and electrics
    2% of testsRough price £10–£80

    At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.

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Other years

YearMOT testsMost flagged
2022389Tyres 25%
2020188Tyres 23%

Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2021 BMW 318Is registered in 2021. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score