Used car guide

2017 Mercedes-Benz CLA: common problems and what to check

What gets flagged at MOT on 2017 Mercedes-Benz CLAs, from 8,245 tests in 2025, plus known faults and what to look at before you buy one.

8,245MOT tests in 2025
77%pass first time (all 2017 cars: 78%)
8,700typical miles a year
5.2×the usual rate for link ball joint covers

What stands out

Parts flagged at MOT more often on 2017 Mercedes-Benz CLAs than on all cars registered in 2017.

  • Link ball joint covers5.2× usual
    Mercedes-Benz CLA
    2.6% All 2017 cars
    0.5%

    Failed outright at MOT: 1.3%, against 0.3% of all 2017 cars. The rest were advisories or minor defects.

    Rough price £60–£150 (one joint) ClickMechanic

    At the viewing: Listen for knocking over bumps and check the rubber boots behind the wheels aren't split.

  • Engine warning light2.5× usual
    Mercedes-Benz CLA
    3.3% All 2017 cars
    1.3%

    Failed outright at MOT: 3.3%, against 1.3% of all 2017 cars. The rest were advisories or minor defects.

    Rough price £10–£80 our estimate

    At the viewing: Ask a friend to check every light while you work the switches: indicators, brake lights, fog lights and reversing lights.

  • Wheels2.7× usual
    Mercedes-Benz CLA
    2.7% All 2017 cars
    1%

    Failed outright at MOT: 1.2%, against 0.3% of all 2017 cars. The rest were advisories or minor defects.

    Rough price £70–£150 our estimate

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

Better than most

Suspension arm bushes and joints: 0.4% here, against 4.8% of all 2017 cars.

By area

The share of 2017 Mercedes-Benz CLA MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Tyres
    33% 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.

  • Suspension
    11% 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.

  • Lights and electrics
    7% 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
    7% of testsRough price £15–£250

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

  • Seats and seatbelts
    2% of testsRough price £80–£250

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

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Other years

YearMOT testsMost flagged
2023696Tyres 13%
202211,367Tyres 29%
20219,544Tyres 30%
20207,521Tyres 31%
20198,245Tyres 32%
20188,402Tyres 33%
20167,601Tyres 33%
20156,749Tyres 33%
20144,276Tyres 33%
20132,080Tyres 34%

Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2017 Mercedes-Benz CLAs registered in 2017. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score