Used car guide

1998 Mercedes-Benz C-Class: common problems and what to check

What gets flagged at MOT on 1998 Mercedes-Benz C-Classs, from 747 tests in 2025, plus known faults and what to look at before you buy one.

747MOT tests in 2025
71%pass first time (all 1998 cars: 66%)
4,100typical miles a year
2.5×the usual rate for sub-frame

What stands out

Parts flagged at MOT more often on 1998 Mercedes-Benz C-Classs than on all cars registered in 1998.

  • Sub-frame2.5× usual
    Mercedes-Benz C-Class
    8% All 1998 cars
    3.2%

    Failed outright at MOT: 0%, against 0.1% of all 1998 cars. The rest were advisories or minor defects.

    Rough price £300–£1,000 our estimate

    At the viewing: Look underneath at the frame the suspension bolts to. Flaky rust or holes are expensive to fix.

  • Side repeaters4.7× usual
    Mercedes-Benz C-Class
    5.2% All 1998 cars
    1.1%

    Failed outright at MOT: 2.3%, against 0.8% of all 1998 cars. The rest were advisories or minor defects.

    Rough price £10–£80 our estimate

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

  • Individual direction indicators2.1× usual
    Mercedes-Benz C-Class
    6.7% All 1998 cars
    3.2%

    Failed outright at MOT: 2.1%, against 1.5% of all 1998 cars. The rest were advisories or minor defects.

    Rough price £10–£80 our estimate

    At the viewing: Ask a friend to check every light while you work the switches: indicators, brake lights, fog lights and reversing lights.

Better than most

Exhaust system: 3.7% here, against 8.6% of all 1998 cars.

By area

The share of 1998 Mercedes-Benz C-Class MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Suspension
    37% 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
    34% 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.

  • Lights and electrics
    28% of testsRough price £10–£80

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

  • Tyres
    23% 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.

  • Oil and fluid leaks
    16% 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.

  • Rust and bodywork
    9% of testsRough price £150–£1,000

    At the viewing: Check the sills, wheel arches and underneath for rust, and look along the panels for uneven gaps or paint.

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Other years

YearMOT testsMost flagged
2023355Tyres 16%
20224,604Tyres 27%
20215,709Tyres 27%
20209,919Tyres 30%
201924,634Tyres 29%
201828,346Tyres 29%
201739,535Tyres 29%
201636,616Tyres 30%
201534,042Tyres 30%
201425,210Tyres 32%
201323,494Suspension 33%
201225,753Brakes 40%
201118,838Brakes 40%
201012,845Brakes 40%
200912,668Suspension 43%
200813,214Suspension 44%
200711,454Suspension 50%
20068,786Suspension 57%
20057,282Suspension 59%
20045,380Suspension 59%
20033,648Suspension 54%
20022,021Suspension 49%
20011,080Suspension 46%
2000523Suspension 41%
1999674Suspension 36%
1997611Suspension 44%
1996368Suspension 36%
1995268Brakes 34%
1994222Suspension 36%

Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 1998 Mercedes-Benz C-Classs registered in 1998. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score