Used car guide

2020 Mercedes-Benz GLC: common problems and what to check

What gets flagged at MOT on 2020 Mercedes-Benz GLCs, from 11,103 tests in 2025, plus known faults and what to look at before you buy one.

11,103MOT tests in 2025
90%pass first time (all 2020 cars: 86%)
8,400typical miles a year
10.5×the usual rate for ball joint

What stands out

Parts flagged at MOT more often on 2020 Mercedes-Benz GLCs than on all cars registered in 2020.

  • Ball joint10.5× usual
    Mercedes-Benz GLC
    6.3% All 2020 cars
    0.6%

    Failed outright at MOT: 1.8%, against 0.2% of all 2020 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.

By area

The share of 2020 Mercedes-Benz GLC MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Tyres
    25% 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
    13% 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
    7% 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.

  • 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.

  • 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.

Looking at a Mercedes-Benz GLC?

Check the actual car: its own MOT history, mileage and what to ask the seller. Free, no sign-up.

Other years

YearMOT testsMost flagged
20227,144Tyres 26%
20216,537Tyres 25%
201917,168Tyres 26%
201818,893Tyres 27%
201712,478Tyres 27%
20169,086Tyres 27%
20151,312Tyres 26%

Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2020 Mercedes-Benz GLCs registered in 2020. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score