Used car guide

2017 Mazda 6 diesel: common problems and MOT failures

What MOT testers find on the diesel Mazda 6 first registered in 2017 (diesel cars only): we looked at the 8,456 MOTs these cars had during 2023–2025. Plus known faults and what to look at before you buy one.

8,456MOTs of 2017 diesel cars, done in 2023–2025
79%pass first time (all 2017 cars: 80%)
10,400typical miles a year
4.3×the usual rate for rigid brake pipes

What goes wrong more than usual on a 2017 Mazda 6 diesel?

Parts flagged at MOT more often on the 2017 Mazda 6 diesel than on all cars registered in 2017.

  • Rigid brake pipes4.3× usual
    Mazda 6
    4.3% All 2017 cars
    1%

    Failed outright at MOT: 0.7%, against 0.1% of all 2017 cars. The rest were advisories or minor defects.

    Rough price £100–£400 our estimate

    At the viewing: Ask to see underneath, or check the MOT advisories: corroded brake or fuel pipes get worse every year and fail the MOT when they do.

  • Suspension arm bushes and joints1.8× usual
    Mazda 6
    6.5% All 2017 cars
    3.7%

    Failed outright at MOT: 0.3%, against 0.7% of all 2017 cars. The rest were advisories or minor defects.

    Rough price £120–£180 (one arm) ClickMechanic

    At the viewing: Listen for clunks over bumps and feel for the steering wandering. Worn arm bushes show as cracked rubber near the wheels.

  • Wheels2.3× usual
    Mazda 6
    2.1% All 2017 cars
    0.9%

    Failed outright at MOT: 0.4%, against 0.3% of all 2017 cars. The rest were advisories or minor defects.

    Rough price £70–£150 our estimate

    At the viewing: Check the tread on all four tyres, including the inside edges, and look for cracks or bulges.

  • Ball joint1.9× usual
    Mazda 6
    2.6% All 2017 cars
    1.4%

    Failed outright at MOT: 1.6%, against 0.7% of all 2017 cars. The rest were advisories or minor defects.

    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.

Common 2017 Mazda 6 diesel MOT failures and advisories

The share of 2017 Mazda 6 diesel MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Tyres
    31% 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
    28% 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
    17% 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
    8% 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
    6% 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
    3% of testsRough price £80–£250

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

Known faults on the 2017 Mazda 6 diesel

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.

  • Diesel in the oil (particulate filter)

    Diesel

    If the engine is switched off during particulate filter cleaning, fuel can get into the oil and raise the level, which can damage the engine.

    At the viewing: Check the oil isn’t above the max mark and ask what journeys it does.

    Source: What Car?: used Mazda 6 (2013-2022) reliability

  • Airbag inflator and boot strut recalls

    All engines

    Driver’s airbag inflators can rupture after long exposure to humidity and must be replaced, and boot struts were recalled in 2017.

    At the viewing: Ask a Mazda dealer to confirm the recalls were done.

    Source: What Car?: used Mazda 6 (2013-2022) reliability

  • Warped brake discs

    All engines

    It can be hard on its brake discs, causing vibration under braking.

    At the viewing: Brake firmly from speed and feel for shaking.

    Source: What Car?: used Mazda 6 (2013-2022) reliability

Questions to ask the seller before buying a 2017 Mazda 6 diesel

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

  1. Does it do regular motorway runs?
  2. Any recent work on the rigid brake pipes? (Flagged at MOT 4.3× as often on the 2017 Mazda 6 diesel as on other cars the same age.)
  3. Any recent work on the suspension arm bushes and joints? (Flagged at MOT 1.8× as often on the 2017 Mazda 6 diesel as on other cars the same age.)
  4. Any recent work on the wheels? (Flagged at MOT 2.3× as often on the 2017 Mazda 6 diesel as on other cars the same age.)
  5. Can I see the service history and receipts for any big jobs?

Looking at a Mazda 6?

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 Mazda 6 compared

YearMOT testsMost flagged
2023–Too new for MOT data
2022754Tyres 15%
20211,288Tyres 22%
20203,120Tyres 22%
201913,161Tyres 26%
20189,631Tyres 29%
201620,504Brakes 29%
201519,689Tyres 30%
201418,402Suspension 34%
201312,297Suspension 39%
20128,508Brakes 41%
201111,812Brakes 42%
201015,127Brakes 44%
200911,548Suspension 46%
200810,079Suspension 48%
20076,991Suspension 53%
20064,017Suspension 50%
20052,451Suspension 51%
20041,127Suspension 52%
2003577Suspension 55%
2002228Suspension 53%

Where this comes from: the DVSA's anonymised results for every MOT test done in Great Britain during 2023–2025, counting the MOTs of Mazda 6 cars first registered in 2017. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score