2020 BMW 520I M Sport Mhev Auto: common problems and what to check
What gets flagged at MOT on 2020 BMW 520I M Sport Mhev Autos, from 103 tests in 2025, plus known faults and what to look at before you buy one.
Small sample: only 103 of these were MOT tested in 2025, so treat the percentages as rough. The known faults below don't depend on it.
What gets flagged at MOT
The share of 2020 BMW 520I M Sport Mhev Auto MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.
- Tyres22% 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.
- Seats and seatbelts5% of testsRough price £80–£250
At the viewing: Pull each seatbelt sharply. It should lock, and retract cleanly.
- Lights and electrics3% of testsRough price £10–£80
At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.
- Brakes2% 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.
- Rust and bodywork1% of testsRough price £150–£1,000
At the viewing: Check the sills, wheel arches and underneath for rust, and look along the panels for uneven gaps or paint.
- Suspension1% 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
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 recallsAll 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 faultsAll 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
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Other years
| Year | MOT tests | Most flagged |
|---|---|---|
| 2022 | 506 | Tyres 20% |
| 2021 | 438 | Tyres 24% |
Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2020 BMW 520I M Sport Mhev Autos registered in 2020. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score