Used car guide

2004 Mercedes-Benz A-Class: common problems and MOT failures

What MOT testers find on the Mercedes-Benz A-Class first registered in 2004: we looked at the 907 MOTs these cars had during 2025. Plus known faults and what to look at before you buy one.

907MOTs of 2004 cars, done 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 goes wrong more than usual on a 2004 Mercedes-Benz A-Class?

Parts flagged at MOT more often on the 2004 Mercedes-Benz A-Class 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.

Common 2004 Mercedes-Benz A-Class MOT failures and advisories

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.

  • 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.

  • 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.

Questions to ask the seller before buying a 2004 Mercedes-Benz A-Class

Ask before you travel to see it. A seller who knows the car will have answers, and receipts.

  1. Any recent work on the rigid brake pipes? (Flagged at MOT 2.1× as often on the 2004 Mercedes-Benz A-Class as on other cars the same age.)
  2. Any recent work on the shock absorbers? (Flagged at MOT 2.8× as often on the 2004 Mercedes-Benz A-Class as on other cars the same age.)
  3. Any recent work on the flexible brake hoses? (Flagged at MOT 2.1× as often on the 2004 Mercedes-Benz A-Class as on other cars the same age.)
  4. Can I see the service history and receipts for any big jobs?

Looking at a Mercedes-Benz A-Class?

Check the actual car: its own MOT history, mileage and what to ask the seller. Free, no sign-up.

Other years

Every year of the Mercedes-Benz A-Class compared

YearMOT testsMost flagged
2026–Too new for MOT data
2025–Too new for MOT data
2024–Too new for MOT data
2023734Tyres 13%
202217,786Tyres 24%
202129,555Tyres 26%
2020106Tyres 30%
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%
2001448Suspension 50%
2000163Suspension 53%
1999123Suspension 52%
1998–Too few tests

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