Used car guide

2018 BMW 520: common problems and what to check

What gets flagged at MOT on 2018 BMW 520s, from 184 tests in 2025, plus known faults and what to look at before you buy one.

Small sample: only 184 of these were MOT tested in 2025, so treat the percentages as rough. The known faults below don't depend on it.

184MOT tests in 2025
89%pass first time (all 2018 cars: 81%)
9,400typical miles a year
22%had tyres flagged

What gets flagged at MOT

The share of 2018 BMW 520 MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Tyres
    22% 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.

  • Brakes
    12% 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
    12% 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
    4% of testsRough price £10–£80

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

  • Seats and seatbelts
    4% of testsRough price £80–£250

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

  • 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.

Known faults

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

Looking at a BMW 520?

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

Other years

YearMOT testsMost flagged
2019122Tyres 20%
20171,462Tyres 26%
201611,923Tyres 26%
201512,114Tyres 27%
201411,329Tyres 28%
20136,481Tyres 29%
20126,020Tyres 31%
20116,844Tyres 31%
20103,675Suspension 33%
20093,423Suspension 39%
20082,220Suspension 42%
20072,434Suspension 50%
20061,564Suspension 50%
2005412Suspension 52%
2004184Suspension 50%
2003313Suspension 44%
2002278Suspension 43%
2001209Suspension 45%
2000106Suspension 46%
1999116Suspension 51%

Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2018 BMW 520s registered in 2018. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score