Used car guide

2006 Mazda 6 diesel: common problems and MOT failures

What MOT testers find on the diesel Mazda 6 first registered in 2006 (diesel cars only): we looked at the 344 MOTs these cars had during 2023–2025. Plus known faults and what to look at before you buy one.

Small sample: there were only 344 MOTs of these cars during 2023–2025, so treat the percentages as rough. The known faults below don't depend on it.

344MOTs of 2006 diesel cars, done in 2023–2025
53%pass first time (all 2006 cars: 56%)
6,400typical miles a year
3.9×the usual rate for rust around suspension or steering mountings

What goes wrong more than usual on a 2006 Mazda 6 diesel?

Parts flagged at MOT more often on the 2006 Mazda 6 diesel than on all cars registered in 2006.

  • Rust around suspension or steering mountings3.9× usual
    Mazda 6
    18.6% All 2006 cars
    4.8%

    Failed outright at MOT: 11.6%, against 2.3% of all 2006 cars. The rest were advisories or minor defects.

    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.

  • Sub-frame3.4× usual
    Mazda 6
    18% All 2006 cars
    5.3%

    Failed outright at MOT: 0.6%, against 0.3% of all 2006 cars. The rest were advisories or minor defects.

    Rough price £300–£1,000 our estimate

    At the viewing: Look underneath at the frame the suspension bolts to. Flaky rust or holes are expensive to fix.

  • Braking performance2.7× usual
    Mazda 6
    18.6% All 2006 cars
    6.9%

    Failed outright at MOT: 7%, against 2.9% of all 2006 cars. The rest were advisories or minor defects.

    Rough price £100–£350 our estimate

    At the viewing: On a quiet road, brake firmly from about 30mph. The car should stop straight without pulling.

  • Ball joint dust cover3.2× usual
    Mazda 6
    14.5% All 2006 cars
    4.5%

    Failed outright at MOT: 4.9%, against 1.9% of all 2006 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.

  • Suspension arm3.8× usual
    Mazda 6
    11.3% All 2006 cars
    3%

    Failed outright at MOT: 0.9%, against 0.3% of all 2006 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.

Common 2006 Mazda 6 diesel MOT failures and advisories

The share of 2006 Mazda 6 diesel MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Suspension
    56% 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.

  • Brakes
    46% 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
    37% of testsRough price £10–£80

    At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.

  • Tyres
    36% 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.

  • Rust and bodywork
    23% 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.

  • Oil and fluid leaks
    18% of testsRough price £80–£600

    At the viewing: Look under the engine and on the ground where the car is usually parked for fresh oil or fluid.

Questions to ask the seller before buying a 2006 Mazda 6 diesel

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

  1. Any recent work on the rust around suspension or steering mountings? (Flagged at MOT 3.9× as often on the 2006 Mazda 6 diesel as on other cars the same age.)
  2. Any recent work on the sub-frame? (Flagged at MOT 3.4× as often on the 2006 Mazda 6 diesel as on other cars the same age.)
  3. Any recent work on the braking performance? (Flagged at MOT 2.7× as often on the 2006 Mazda 6 diesel as on other cars the same age.)
  4. 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%
201714,007Tyres 30%
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%
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 2006. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score