2004 BMW 520i: common problems and MOT failures

What goes wrong more than usual on a 2004 BMW 520i?

Parts flagged at MOT more often on the 2004 BMW 520i than on all cars registered in 2004.

• Engine oil leaks2.4× usual
  BMW 520i

  34.1% All 2004 cars

  14.5%

  Failed outright at MOT: 1.4%, against 0.4% of all 2004 cars. The rest were advisories or minor defects.

  Rough price £80–£600 our estimate

  At the viewing: Look under the engine and where the car is usually parked for fresh oil. Ask whether the leak has been looked at.

• Suspension arm bushes and joints2.3× usual
  BMW 520i

  21% All 2004 cars

  9.3%

  Failed outright at MOT: 4%, against 2.1% of all 2004 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.

• Airbag warning light4.6× usual
  BMW 520i

  7.8% All 2004 cars

  1.7%

  Failed outright at MOT: 7%, against 1.5% of all 2004 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.

• Steering rack inner joints2.2× usual
  BMW 520i

  8% All 2004 cars

  3.7%

  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.

• Link ball joint covers2.2× usual
  BMW 520i

  6% All 2004 cars

  2.7%

  Failed outright at MOT: 2.7%, against 1.5% of all 2004 cars. The rest were advisories or minor defects.

  Rough price £60–£150 (one joint) ClickMechanic

  At the viewing: Listen for knocking over bumps and check the rubber boots behind the wheels aren't split.

Common 2004 BMW 520i MOT failures and advisories

The share of 2004 BMW 520i MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

• Suspension
  45% 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
  37% 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
  36% of testsRough price £10–£80

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

• Oil and fluid leaks
  35% 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.

• 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.

• Wipers, windscreen and mirrors
  11% of testsRough price £15–£250

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

Questions to ask the seller before buying a 2004 BMW 520i

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

1. Any recent work on the engine oil leaks? (Flagged at MOT 2.4× as often on the 2004 BMW 520i as on other cars the same age.)
2. Any recent work on the suspension arm bushes and joints? (Flagged at MOT 2.3× as often on the 2004 BMW 520i as on other cars the same age.)
3. Any recent work on the airbag warning light? (Flagged at MOT 4.6× as often on the 2004 BMW 520i as on other cars the same age.)
4. Can I see the service history and receipts for any big jobs?