2018 MG 3: common problems and MOT failures

What goes wrong more than usual on a 2018 MG 3?

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

• Suspension arm41× usual
  MG 3

  4.1% All 2018 cars

  0.1%

  Failed outright at MOT: 0%, against 0% of all 2018 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.

• Sub-frame38× usual
  MG 3

  3.8% All 2018 cars

  0.1%

  Failed outright at MOT: 0.1%, against 0% of all 2018 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.

• Coil springs3.9× usual
  MG 3

  4.3% All 2018 cars

  1.1%

  Failed outright at MOT: 2.3%, 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.

• Rigid brake pipes7.2× usual
  MG 3

  3.6% All 2018 cars

  0.5%

  Failed outright at MOT: 0.5%, 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.

• Braking performance3.1× usual
  MG 3

  3.7% All 2018 cars

  1.2%

  Failed outright at MOT: 1.4%, against 0.4% of all 2018 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.

Common 2018 MG 3 MOT failures and advisories

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

• Tyres
  32% 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
  25% 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
  15% 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
  10% 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
  8% of testsRough price £15–£250

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

• Oil and fluid leaks
  2% 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.

Known faults on the 2018 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 2018 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 suspension arm? (Flagged at MOT 41× as often on the 2018 MG 3 as on other cars the same age.)
3. Any recent work on the sub-frame? (Flagged at MOT 38× as often on the 2018 MG 3 as on other cars the same age.)
4. Any recent work on the coil springs? (Flagged at MOT 3.9× as often on the 2018 MG 3 as on other cars the same age.)
5. Can I see the service history and receipts for any big jobs?