Used car guide

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

What gets flagged at MOT on 2017 Mercedes-Benz GLSs, from 605 tests in 2025, plus known faults and what to look at before you buy one.

605MOT tests in 2025
89%pass first time (all 2017 cars: 78%)
9,000typical miles a year
30%had tyres flagged

What gets flagged at MOT

The share of 2017 Mercedes-Benz GLS 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
    14% 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
    5% of testsRough price £15–£250

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

  • Driveshafts and joints
    4% of testsRough price £60–£350

    At the viewing: On full steering lock, drive slowly and listen for clicking from the front wheels.

  • Lights and electrics
    4% of testsRough price £10–£80

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

  • Oil and fluid leaks
    2% 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.

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Other years

YearMOT testsMost flagged
2018556Tyres 27%

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