Used car guide

2018 Hyundai I40: common problems and what to check

What gets flagged at MOT on 2018 Hyundai I40s, from 1,130 tests in 2025, plus known faults and what to look at before you buy one.

1,130MOT tests in 2025
81%pass first time (all 2018 cars: 81%)
11,200typical miles a year
3×the usual rate for engine oil leaks

What stands out

Parts flagged at MOT more often on 2018 Hyundai I40s than on all cars registered in 2018.

  • Engine oil leaks3× usual
    Hyundai I40
    4.2% All 2018 cars
    1.4%

    Failed outright at MOT: 0%, against 0% of all 2018 cars. The rest were advisories or minor defects.

    Rough price £80–£600 our estimate

    At the viewing: Look under the engine and where the car is usually parked for fresh oil. Ask whether the leak has been looked at.

  • Headlights2.5× usual
    Hyundai I40
    2.7% All 2018 cars
    1.1%

    Failed outright at MOT: 2.6%, against 1% of all 2018 cars. The rest were advisories or minor defects.

    Rough price £40–£400 our estimate

    At the viewing: Check both headlights on dipped and full beam, and look for cloudy or cracked lenses.

By area

The share of 2018 Hyundai I40 MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Tyres
    30% 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
    22% 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.

  • Lights and electrics
    11% of testsRough price £10–£80

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

  • Wipers, windscreen and mirrors
    5% of testsRough price £15–£250

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

  • Suspension
    5% 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.

  • Oil and fluid leaks
    5% of testsRough price £80–£600

    At the viewing: Look under the engine and on the ground where the car is usually parked for fresh oil or fluid.

Looking at a Hyundai I40?

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Other years

YearMOT testsMost flagged
20172,456Tyres 32%
20163,355Tyres 30%
20153,366Brakes 33%
20143,371Brakes 36%
20132,474Brakes 39%
20122,803Suspension 45%

Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2018 Hyundai I40s registered in 2018. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score