2021 MG 3: common problems and MOT failures

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

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

• Tyre condition1.8× usual
  MG 3

  18.4% All 2021 cars

  10.4%

  Failed outright at MOT: 4.6%, against 3.6% of all 2021 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. Uneven wear can point to tracking or suspension problems.

• Headlight aim3.3× usual
  MG 3

  4.9% All 2021 cars

  1.5%

  Failed outright at MOT: 4.9%, against 1.5% of all 2021 cars. The rest were advisories or minor defects.

  Rough price £20–£60 our estimate

  At the viewing: Park facing a wall at night or in a garage and check both headlight beams sit level. Aim is a cheap adjustment.

Common 2021 MG 3 MOT failures and advisories

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

• Tyres
  29% 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
  13% 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
  9% 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.

• Suspension
  3% 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.

• 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 2021 MG 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.

• Timing chain stretch (early cars)

  Early cars

  On early cars the timing chain can stretch and jump a tooth, causing rough running and poor starting, and eventually engine failure. An upgraded chain is available.

  At the viewing: Listen for a rattle at start-up and check it starts and idles smoothly.

  Source: What Car?: MG 3 (2013-2024) reliability

• Clutch pedal sticking down

  All engines

  On some cars the clutch pedal has gone to the floor and not come back.

  At the viewing: Press the clutch several times and make sure it returns fully every time.

  Source: What Car?: MG 3 (2013-2024) reliability

• Leaky door seals (early cars)

  Early cars

  Some early cars let water in past the door seals.

  At the viewing: Feel the carpets and seats for damp.

  Source: What Car?: MG 3 (2013-2024) reliability

• Sensor faults and fuel tank strap recall

  All engines

  Rear parking sensors and other sensors and displays can fail. A recall covered fuel tank strap bolts that weren't made to the right spec.

  At the viewing: Test the parking sensors and run the free DVSA recall check on the reg.

  Source: What Car?: MG 3 (2013-2024) reliability

Questions to ask the seller before buying a 2021 MG 3

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

1. Has the upgraded timing chain been fitted?
2. Any recent work on the tyre condition? (Flagged at MOT 1.8× as often on the 2021 MG 3 as on other cars the same age.)
3. Any recent work on the headlight aim? (Flagged at MOT 3.3× as often on the 2021 MG 3 as on other cars the same age.)
4. Can I see the service history and receipts for any big jobs?