2021 BMW 520: common problems and MOT failures

What goes wrong more than usual on a 2021 BMW 520?

Parts flagged at MOT more often on the 2021 BMW 520 than on all cars registered in 2021.

• Flexible couplingsnull× usual
  BMW 520

  4.1% All 2021 cars

  0%

  Failed outright at MOT: 0.3%, against 0% of all 2021 cars. The rest were advisories or minor defects.

  Rough price £150–£1,000 our estimate

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

Common 2021 BMW 520 MOT failures and advisories

The share of 2021 BMW 520 MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

• Tyres
  25% 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.

• Lights and electrics
  6% of testsRough price £10–£80

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

• Brakes
  3% 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.

• Wipers, windscreen and mirrors
  3% of testsRough price £15–£250

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

• Seats and seatbelts
  2% of testsRough price £80–£250

  At the viewing: Pull each seatbelt sharply. It should lock, and retract cleanly.

• Suspension
  1% 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.

Known faults on the 2021 BMW 520

Reported by owners, mechanics and buying guides for this model and age. Check which engine the car has, as some apply to one engine only.

• EGR and particulate filter problems (diesel)

  Diesel

  Diesels came last of 20 executive cars in What Car?'s survey, with costly EGR valve and DPF faults and repeat dealer visits. There were also EGR cooler and coolant recalls for fire risk.

  At the viewing: Ask a BMW dealer to check the VIN for recalls, and watch for warning lights.

  Source: What Car?: used BMW 5 Series (2017-2023) reliability

• Ten recalls

  All engines

  Recalls also covered the brake pedal switch, curtain airbags, the steering gear, a balance shaft bearing, 48-volt battery cables, rear driveshafts and plug-in hybrid batteries.

  At the viewing: Ask a BMW dealer to confirm every recall has been done.

  Source: What Car?: used BMW 5 Series (2017-2023) reliability

• Electrical and sensor faults

  All engines

  Most petrol faults are electrical, including faulty sensors, persistent warning lights and infotainment faults.

  At the viewing: Test every button and screen, and look for warning lights.

  Source: What Car?: used BMW 5 Series (2017-2023) reliability

Questions to ask the seller before buying a 2021 BMW 520

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

1. Have the EGR recalls been done, and has it had any EGR or DPF work?
2. Any recent work on the flexible couplings? (Flagged at MOT null× as often on the 2021 BMW 520 as on other cars the same age.)
3. Can I see the service history and receipts for any big jobs?