2002 Mercedes-Benz A-Class diesel: common problems and MOT failures

What goes wrong more than usual on a 2002 Mercedes-Benz A-Class diesel?

Parts flagged at MOT more often on the 2002 Mercedes-Benz A-Class diesel than on all cars registered in 2002.

• Rigid brake pipes2× usual
  Mercedes-Benz A-Class

  36.1% All 2002 cars

  18.2%

  Failed outright at MOT: 5.3%, against 2.9% of all 2002 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

  17.2% All 2002 cars

  6.2%

  Failed outright at MOT: 4.4%, against 1.5% of all 2002 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.

• Diesel smoke emissions14.7× usual
  Mercedes-Benz A-Class

  10.3% All 2002 cars

  0.7%

  Failed outright at MOT: 8.8%, against 0.6% of all 2002 cars. The rest were advisories or minor defects.

  Rough price £175–£900 (catalytic converter) ClickMechanic

  At the viewing: Look for smoke when revving the warm engine and for engine or DPF warning lights.

• Suspension arm bushes and joints2× usual
  Mercedes-Benz A-Class

  16.6% All 2002 cars

  8.3%

  Failed outright at MOT: 4.4%, against 1.9% of all 2002 cars. The rest were advisories or minor defects.

  Rough price £120–£180 (one arm) ClickMechanic

  At the viewing: Listen for clunks over bumps and feel for the steering wandering. Worn arm bushes show as cracked rubber near the wheels.

• Steering rack inner joints2.8× usual
  Mercedes-Benz A-Class

  9.7% All 2002 cars

  3.5%

  Failed outright at MOT: 0%, against 0% of all 2002 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.

Common 2002 Mercedes-Benz A-Class diesel MOT failures and advisories

The share of 2002 Mercedes-Benz A-Class diesel MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

• Brakes
  52% 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
  50% 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
  37% 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
  32% 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.

• Exhaust and emissions
  16% of testsRough price £100–£1,200

  At the viewing: Look for black soot in the tailpipe, listen for blowing from the exhaust and check for engine or DPF warning lights.

• Steering
  14% 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 2002 Mercedes-Benz A-Class diesel

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× as often on the 2002 Mercedes-Benz A-Class diesel as on other cars the same age.)
2. Any recent work on the shock absorbers? (Flagged at MOT 2.8× as often on the 2002 Mercedes-Benz A-Class diesel as on other cars the same age.)
3. Any recent work on the diesel smoke emissions? (Flagged at MOT 14.7× as often on the 2002 Mercedes-Benz A-Class diesel as on other cars the same age.)
4. Can I see the service history and receipts for any big jobs?