Used car guide

2021 Mercedes-Benz EQC 400 AMG Line Premium + 4M: common problems and what to check

What gets flagged at MOT on 2021 Mercedes-Benz EQC 400 AMG Line Premium + 4Ms, from 1,412 tests in 2025, plus known faults and what to look at before you buy one.

1,412MOT tests in 2025
84%pass first time (all 2021 cars: 87%)
8,500typical miles a year
11.7×the usual rate for ball joint

What stands out

Parts flagged at MOT more often on 2021 Mercedes-Benz EQC 400 AMG Line Premium + 4Ms than on all cars registered in 2021.

  • Ball joint11.7× usual
    Mercedes-Benz EQC 400 AMG Line Premium + 4M
    7% All 2021 cars
    0.6%

    Failed outright at MOT: 2.7%, against 0.2% of all 2021 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.

Better than most

Brake pads: 1.4% here, against 6.8% of all 2021 cars. Brake discs: 2.7% here, against 7.1% of all 2021 cars.

By area

The share of 2021 Mercedes-Benz EQC 400 AMG Line Premium + 4M 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.

  • Suspension
    8% 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.

  • Brakes
    4% 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.

  • 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.

  • 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
20222,378Tyres 34%
2020625Tyres 32%

Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2021 Mercedes-Benz EQC 400 AMG Line Premium + 4Ms registered in 2021. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score