BMW 520i common problems and MOT failures

What usually goes wrong with a BMW 520i?

Known faults reported by owners, mechanics and UK buying guides, in our own words. Most apply to certain years or engines only, so check which the car has.

• Timing chain wear

  Cars registered 2012–2016 · All engines

  Wear in the timing chain guides and tensioner shows up as a grinding or rattling noise at start-up. Putting it right is a big job with a big bill.

  At the viewing: Start the engine from cold and listen for grinding or rattling in the first few seconds.

  Source: Haynes: BMW 5-Series common problems (2010-2017)

• EGR and particulate filter problems (diesel)

  Cars registered 2018–2022 · 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

• EGR cooler recall (diesel)

  Cars registered 2012–2016 · Diesel

  Over 220,000 BMWs were recalled because the EGR cooler could leak and, in rare cases, cause a fire.

  At the viewing: Ask a BMW dealer to check the VIN for outstanding recalls.

  Source: Haynes: BMW 5-Series common problems (2010-2017)

• Wet passenger footwell

  Cars registered 2012–2016 · All engines

  A leak at the heater blower housing can soak the front passenger carpet, often noticed as a musty smell.

  At the viewing: Feel the passenger-side carpet for damp and sniff for mustiness.

  Source: Haynes: BMW 5-Series common problems (2010-2017)

• Cranks but won’t start

  Cars registered 2012–2016 · All engines

  A failing fuel pump control unit can stop the engine firing even though it turns over. It has to be replaced.

  At the viewing: Make sure it starts promptly every time you try.

  Source: Haynes: BMW 5-Series common problems (2010-2017)

• Ten recalls

  Cars registered 2018–2022 · 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

  Cars registered 2018–2022 · 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

• Noisy or odd-feeling steering

  Cars registered 2012–2016 · All engines

  Air getting into the power steering, usually from a failing pump, makes the steering noisy.

  At the viewing: Turn the wheel lock to lock with the engine running and listen for whining.

  Source: Haynes: BMW 5-Series common problems (2010-2017)

• Ticking from a front wheel

  Cars registered 2012–2016 · All engines

  A brake disc that sits too close to the wheel bearing can tick on every turn. A small spacer fixes it.

  At the viewing: Drive slowly with the window down and listen for ticking.

  Source: Haynes: BMW 5-Series common problems (2010-2017)

Common BMW 520i MOT failures to check

Parts flagged at MOT well above the usual rate for cars the same age, in more than one year. From the DVSA’s results for every MOT done in Great Britain during 2023–2025.

• Link ball joint covers

  up to 3.5× usual

  Stands out on cars registered in 2001, 2002, 2003 and 2004.

  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.

• Engine oil leaks

  up to 2.4× usual

  Stands out on cars registered in 2001, 2002, 2003 and 2004.

  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.

• Anti-roll bar link joints

  up to 3.7× usual

  Stands out on cars registered in 2001, 2002 and 2003.

  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.

• Airbag warning light

  up to 4.6× usual

  Stands out on cars registered in 2003 and 2004.

  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

  up to 3.2× usual

  Stands out on cars registered in 2001 and 2002.

  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.

BMW 520i MOT pass rate by year

Of the years since 2005 with plenty of MOT tests, the 2015 BMW 520i did best (86% passed first time, 12 points above all 2015 cars) and the 2022 did worst (87%, 2 points below all 2022 cars). Older cars fail more, so compare each year with all cars registered the same year.

Questions to ask the seller before buying a BMW 520i

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

1. Has the timing chain or its guides been replaced, and is there an invoice?
2. Have the EGR recalls been done, and has it had any EGR or DPF work?
3. Any recent work on the link ball joint covers? (Flagged at MOT 3.5× as often on the BMW 520i as on other cars the same age.)
4. Any recent work on the engine oil leaks? (Flagged at MOT 2.4× as often on the BMW 520i as on other cars the same age.)
5. Any recent work on the anti-roll bar link joints? (Flagged at MOT 3.7× as often on the BMW 520i as on other cars the same age.)
6. Can I see the service history and receipts for any big jobs?