Used car guide

2004 Mercedes-Benz A-Class: common problems and what to check

What gets flagged at MOT on 2004 Mercedes-Benz A-Classs, from 907 tests in 2025, plus known faults and what to look at before you buy one.

907MOT tests in 2025
54%pass first time (all 2004 cars: 58%)
3,600typical miles a year
2.1×the usual rate for rigid brake pipes

What stands out

Parts flagged at MOT more often on 2004 Mercedes-Benz A-Classs than on all cars registered in 2004.

  • Rigid brake pipes2.1× usual
    Mercedes-Benz A-Class
    35.4% All 2004 cars
    17.1%

    Failed outright at MOT: 5%, against 2.7% of all 2004 cars. The rest were advisories or minor defects.

    Rough price £100–£400 our estimate

    At the viewing: Ask to see underneath, or check the MOT advisories: corroded brake or fuel pipes get worse every year and fail the MOT when they do.

  • Shock absorbers2.8× usual
    Mercedes-Benz A-Class
    19.3% All 2004 cars
    7%

    Failed outright at MOT: 4.9%, against 1.7% of all 2004 cars. The rest were advisories or minor defects.

    Rough price £200–£300 (pair, average rear to front) ClickMechanic

    At the viewing: Push down hard on each corner. It should bounce once and settle. Look for oil on the shock absorber body.

  • Flexible brake hoses2.1× usual
    Mercedes-Benz A-Class
    12% All 2004 cars
    5.7%

    Failed outright at MOT: 1.1%, against 1.2% of all 2004 cars. The rest were advisories or minor defects.

    Rough price £50–£200 our estimate

    At the viewing: Look for cracked or bulging rubber hoses behind the wheels and in the engine bay.

  • Steering rack inner joints2.5× usual
    Mercedes-Benz A-Class
    9.4% All 2004 cars
    3.8%

    Failed outright at MOT: 0%, against 0% of all 2004 cars. The rest were advisories or minor defects.

    Rough price £100–£450 our estimate

    At the viewing: On a straight road the steering wheel should sit straight. Listen for knocks when turning, and check the steering feels even.

  • Number plates1.8× usual
    Mercedes-Benz A-Class
    11.9% All 2004 cars
    6.5%

    Failed outright at MOT: 0.8%, against 0.6% of all 2004 cars. The rest were advisories or minor defects.

    Rough price £5–£40 our estimate

    At the viewing: Check the number plate lights work and the plates are clean and legal.

Better than most

Engine oil leaks: 3.4% here, against 15.8% of all 2004 cars. Track rod ends: 2.3% here, against 6.6% of all 2004 cars.

By area

The share of 2004 Mercedes-Benz A-Class MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Brakes
    51% 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
    47% 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.

  • Lights and electrics
    45% 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
    35% 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.

  • Steering
    15% of testsRough price £100–£450

    At the viewing: On a straight road the steering wheel should sit straight. Feel for play or knocking when turning.

  • Wipers, windscreen and mirrors
    15% of testsRough price £15–£250

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

Looking at a Mercedes-Benz A-Class?

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Other years

YearMOT testsMost flagged
20198,517Tyres 29%
201840,351Tyres 32%
201740,581Tyres 34%
201637,860Tyres 34%
201526,503Tyres 34%
201422,674Tyres 35%
201314,296Tyres 34%
20125,032Brakes 34%
20115,181Brakes 39%
20105,779Brakes 42%
20096,427Brakes 49%
20086,075Brakes 49%
20075,236Brakes 47%
20063,601Brakes 47%
20052,330Brakes 42%
2003974Brakes 54%
2002691Brakes 50%

Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2004 Mercedes-Benz A-Classs registered in 2004. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score