2018 Mazda 3 petrol: common problems and MOT failures

What goes wrong more than usual on a 2018 Mazda 3 petrol?

Parts flagged at MOT more often on the 2018 Mazda 3 petrol than on all cars registered in 2018.

• Brake pads1.7× usual
  Mazda 3

  18.4% All 2018 cars

  10.9%

  Failed outright at MOT: 3.5%, against 2% of all 2018 cars. The rest were advisories or minor defects.

  Rough price £75–£175 (one axle) ClickMechanic

  At the viewing: Listen for squealing or grinding when braking, and look through the wheel at how much pad is left.

• Brake discs1.6× usual
  Mazda 3

  15.6% All 2018 cars

  9.8%

  Failed outright at MOT: 0.8%, against 0.5% of all 2018 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.

• Rigid brake pipes10.8× usual
  Mazda 3

  5.4% All 2018 cars

  0.5%

  Failed outright at MOT: 0.7%, against 0.1% of all 2018 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.

• Coil springs2.6× usual
  Mazda 3

  2.9% All 2018 cars

  1.1%

  Failed outright at MOT: 2.7%, against 0.9% of all 2018 cars. The rest were advisories or minor defects.

  Rough price £175–£400 (pair, one axle) ClickMechanic

  At the viewing: Look behind each wheel for a snapped spring coil, and listen for a clunk or twang when turning the wheel lock to lock with the car stopped.

Common 2018 Mazda 3 petrol MOT failures and advisories

The share of 2018 Mazda 3 petrol MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

• Brakes
  30% 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.

• Tyres
  30% 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.

• Suspension
  6% 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 mirrors
  6% 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.

Known faults on the 2018 Mazda 3 petrol

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.

• Infotainment glitches

  All engines

  There are some reports of glitches and lag with the infotainment and sat nav.

  At the viewing: Try the screen, sat nav and phone connection.

  Source: Auto Express: used Mazda 3 (Mk3, 2014-2019) review

Questions to ask the seller before buying a 2018 Mazda 3 petrol

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 pads? (Flagged at MOT 1.7× as often on the 2018 Mazda 3 petrol as on other cars the same age.)
2. Any recent work on the brake discs? (Flagged at MOT 1.6× as often on the 2018 Mazda 3 petrol as on other cars the same age.)
3. Any recent work on the rigid brake pipes? (Flagged at MOT 10.8× as often on the 2018 Mazda 3 petrol as on other cars the same age.)
4. Can I see the service history and receipts for any big jobs?