2021 Mazda 3: common problems and MOT failures

What goes wrong more than usual on a 2021 Mazda 3?

Parts flagged at MOT more often on the 2021 Mazda 3 than on all cars registered in 2021.

• Brake discs1.6× usual
  Mazda 3

  9.9% All 2021 cars

  6.1%

  Failed outright at MOT: 0.3%, against 0.3% of all 2021 cars. The rest were advisories or minor defects.

  Rough price £150–£350 our estimate

  At the viewing: Look through the wheel at the brake disc: a deep lip at the edge or heavy scoring means they're worn. Feel for judder when braking.

Common 2021 Mazda 3 MOT failures and advisories

The share of 2021 Mazda 3 MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

• Tyres
  24% 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
  15% 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.

• Wipers, windscreen and mirrors
  5% of testsRough price £15–£250

  At the viewing: Check for chips in the driver's view, and test the wipers and washers.

• Lights and electrics
  4% of testsRough price £10–£80

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

• 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.

Known faults on the 2021 Mazda 3

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.

• DPF and emissions faults (diesel)

  Diesel

  Diesels have had particulate filter warnings and emissions system problems.

  At the viewing: Watch for warning lights.

  Source: What Car?: used Mazda 3 (2019 on) reliability

• Minor electrical faults

  Petrol

  Petrol cars have occasional minor faults with the infotainment screen and sensor warnings. Make sure the latest infotainment update is fitted.

  At the viewing: Use the screen and check for warnings.

  Source: What Car?: used Mazda 3 (2019 on) reliability

Questions to ask the seller before buying a 2021 Mazda 3

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

1. Any recent work on the brake discs? (Flagged at MOT 1.6× as often on the 2021 Mazda 3 as on other cars the same age.)
2. Can I see the service history and receipts for any big jobs?