2018 Mercedes-Benz GLC: common problems and what to check
What gets flagged at MOT on 2018 Mercedes-Benz GLCs, from 18,893 tests in 2025, plus known faults and what to look at before you buy one.
What stands out
Parts flagged at MOT more often on 2018 Mercedes-Benz GLCs than on all cars registered in 2018.
- Ball joint8.8× usualMercedes-Benz GLC11.5% All 2018 cars1.3%
Failed outright at MOT: 3.9%, against 0.6% of all 2018 cars. The rest were advisories or minor defects.
Rough price £60–£150 (one joint) ClickMechanicAt the viewing: Listen for knocking over bumps and check the rubber boots behind the wheels aren't split.
- Drive shaft (CV) joints2.8× usualMercedes-Benz GLC3.1% All 2018 cars1.1%
Failed outright at MOT: 2.2%, against 0.6% of all 2018 cars. The rest were advisories or minor defects.
Rough price £60–£350 our estimateAt the viewing: Drive slowly on full steering lock in both directions and listen for clicking. Look for split rubber boots behind the front wheels.
By area
The share of 2018 Mercedes-Benz GLC MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.
- Tyres27% 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.
- Brakes16% 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.
- Suspension13% 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 mirrors5% of testsRough price £15–£250
At the viewing: Check for chips in the driver's view, and test the wipers and washers.
- Seats and seatbelts3% of testsRough price £80–£250
At the viewing: Pull each seatbelt sharply. It should lock, and retract cleanly.
- Driveshafts and joints3% of testsRough price £60–£350
At the viewing: On full steering lock, drive slowly and listen for clicking from the front wheels.
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Other years
| Year | MOT tests | Most flagged |
|---|---|---|
| 2022 | 7,144 | Tyres 26% |
| 2021 | 6,537 | Tyres 25% |
| 2020 | 11,103 | Tyres 25% |
| 2019 | 17,168 | Tyres 26% |
| 2017 | 12,478 | Tyres 27% |
| 2016 | 9,086 | Tyres 27% |
| 2015 | 1,312 | Tyres 26% |
Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2018 Mercedes-Benz GLCs registered in 2018. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score