Used car guide

2020 BMW 6 Series diesel: common problems and MOT failures

What MOT testers find on the diesel BMW 6 Series first registered in 2020 (diesel cars only): we looked at the 609 MOTs these cars had during 2023–2025. Plus known faults and what to look at before you buy one.

609MOTs of 2020 diesel cars, done in 2023–2025
88%pass first time (all 2020 cars: 87%)
9,200typical miles a year
25%had tyres flagged

Common 2020 BMW 6 Series diesel MOT failures and advisories

The share of 2020 BMW 6 Series diesel 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.

  • Brakes
    7% 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.

  • 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.

  • Wipers, windscreen and mirrors
    4% 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.

Questions to ask the seller before buying a 2020 BMW 6 Series diesel

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

  1. Can I see the service history and receipts for any big jobs?

Looking at a BMW 6 Series?

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 6 Series compared

YearMOT testsMost flagged
2026–Too new for MOT data
20193,162Tyres 23%
20184,905Tyres 22%
2017767Tyres 25%
2016–Too few tests
2015–Too few tests
2014–Too few tests
20132,110Tyres 26%
20121,554Tyres 24%
2011229Tyres 20%
2010–Too few tests
2009149Tyres 30%
2008248Suspension 34%
2007254Suspension 33%
2006427Brakes 33%
2005212Brakes 33%
2004–Too few tests
2003–Too few tests
1990–Too few tests
1989–Too few tests
1988–Too few tests
1987–Too few tests
1986–Too few tests
1985–Too few tests
1984–Too few tests
1983–Too few tests
1982–Too few tests
1981–Too few tests
1980–Too few tests
1979–Too few tests
1978–Too few tests
1977–Too few tests

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 6 Series cars first registered in 2020. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score