Used car guide

2021 Mercedes-Benz C200 AMG LN NGT ED Prem Mhev A: common problems and what to check

What gets flagged at MOT on 2021 Mercedes-Benz C200 AMG LN NGT ED Prem Mhev As, from 157 tests in 2025, plus known faults and what to look at before you buy one.

Small sample: only 157 of these were MOT tested in 2025, so treat the percentages as rough. The known faults below don't depend on it.

157MOT tests in 2025
87%pass first time (all 2021 cars: 87%)
8,700typical miles a year
25%had tyres flagged

What gets flagged at MOT

The share of 2021 Mercedes-Benz C200 AMG LN NGT ED Prem Mhev A 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
    6% 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.

  • 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.

  • Suspension
    3% 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.

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

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

Known faults

Reported by owners, mechanics and buying guides for this model and age. Check which engine the car has, as some apply to one engine only.

  • Diesel emissions system faults
    Diesel

    Particulate filter, NOx sensor and AdBlue problems are the main worry on diesels, especially ones used for short trips.

    At the viewing: Watch for emissions or AdBlue warnings on the dash, and ask what journeys it’s done.

    Source: Parkers: Mercedes C-Class (2014-2021) used review

  • Air suspension
    Cars with air suspension

    Cars with air suspension can develop expensive faults that need a specialist.

    At the viewing: Check the car sits level all round, look for uneven front tyre wear, and watch for suspension warnings.

    Source: Parkers: Mercedes C-Class (2014-2021) used review

  • Petrol smell or leaks (petrol)
    Petrol

    Petrol models can leak fuel from the pump area or crack plastic air pipes.

    At the viewing: Smell around the car after a cold start, and listen for rough idle.

    Source: Parkers: Mercedes C-Class (2014-2021) used review

  • Automatic gearbox behaviour
    Automatic

    Some automatics shift inconsistently.

    At the viewing: Drive through every gear at different speeds. Any odd or jerky changes should be priced in or a reason to walk away.

    Source: Parkers: Mercedes C-Class (2014-2021) used review

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Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2021 Mercedes-Benz C200 AMG LN NGT ED Prem Mhev As registered in 2021. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score