2021 BMW 420d: common problems and MOT failures
What MOT testers find on the BMW 420d first registered in 2021: we looked at the 2,795 MOTs these cars had during 2023–2025. Plus known faults and what to look at before you buy one.
Common 2021 BMW 420d MOT failures and advisories
The share of 2021 BMW 420d MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.
- Tyres24% 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 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.
- Brakes3% 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.
- Suspension3% 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.
- Wipers, windscreen and mirrors2% 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 2021 BMW 420d
Ask before you travel to see it. A seller who knows the car will have answers, and receipts.
- Can I see the service history and receipts for any big jobs?
Looking at a BMW 420d?
Check the actual car: its own MOT history, mileage and what to ask the seller. Free, no sign-up.
Other years
Every year of the BMW 420d compared
| Year | MOT tests | Most flagged |
|---|---|---|
| 2022 | 1,335 | Tyres 21% |
| 2020 | 3,280 | Tyres 23% |
| 2019 | 9,324 | Tyres 27% |
| 2018 | 15,717 | Tyres 28% |
| 2017 | 25,828 | Tyres 30% |
| 2016 | 26,407 | Tyres 30% |
| 2015 | 23,877 | Tyres 31% |
| 2014 | 18,932 | Tyres 32% |
| 2013 | 1,390 | Tyres 31% |
Where this comes from: the DVSA's anonymised results for every MOT test done in Great Britain during 2023–2025, counting the MOTs of BMW 420d cars first registered in 2021. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score