2012 Mercedes-Benz A-Class petrol: common problems and MOT failures

What goes wrong more than usual on a 2012 Mercedes-Benz A-Class petrol?

Parts flagged at MOT more often on the 2012 Mercedes-Benz A-Class petrol than on all cars registered in 2012.

• Rigid brake pipes2.7× usual
  Mercedes-Benz A-Class

  13.6% All 2012 cars

  5%

  Failed outright at MOT: 2%, against 0.8% of all 2012 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.

• Side repeaters4.8× usual
  Mercedes-Benz A-Class

  5.8% All 2012 cars

  1.2%

  Failed outright at MOT: 4.8%, against 0.8% of all 2012 cars. The rest were advisories or minor defects.

  Rough price £10–£80 our estimate

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

• Washers1.7× usual
  Mercedes-Benz A-Class

  4.8% All 2012 cars

  2.8%

  Failed outright at MOT: 4.8%, against 2.8% of all 2012 cars. The rest were advisories or minor defects.

  Rough price £15–£60 our estimate

  At the viewing: Test the wipers and washers on every speed.

Common 2012 Mercedes-Benz A-Class petrol MOT failures and advisories

The share of 2012 Mercedes-Benz A-Class 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
  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.

• Lights and electrics
  19% of testsRough price £10–£80

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

• Suspension
  16% 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
  9% of testsRough price £15–£250

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

• Driveshafts and joints
  3% of testsRough price £60–£350

  At the viewing: On full steering lock, drive slowly and listen for clicking from the front wheels.

Known faults on the 2012 Mercedes-Benz A-Class 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.

• Oil leak and engine recalls

  All engines

  Recalls covered engine oil leaks and a fault that could cause engine failure.

  At the viewing: Look for oil under the car and around the engine, and ask a Mercedes dealer to check the VIN.

  Source: Carbuyer: used Mercedes A-Class Mk3 reliability

• Driveshaft recall

  All engines

  A 2015 recall covered the driveshafts.

  At the viewing: Listen for clicking on full lock and feel for vibration when accelerating.

  Source: Carbuyer: used Mercedes A-Class Mk3 reliability

• Electrical faults and rattles

  All engines

  Electrical issues were the top owner complaint, and early cars had seatbelt and dashboard rattles.

  At the viewing: Test every electric function and listen for rattles over bumps.

  Source: Carbuyer: used Mercedes A-Class Mk3 reliability

Questions to ask the seller before buying a 2012 Mercedes-Benz A-Class petrol

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

1. Has all the recall work been done?
2. Has the driveshaft recall been done?
3. Have there been any electrical faults?
4. Any recent work on the rigid brake pipes? (Flagged at MOT 2.7× as often on the 2012 Mercedes-Benz A-Class petrol as on other cars the same age.)
5. Any recent work on the side repeaters? (Flagged at MOT 4.8× as often on the 2012 Mercedes-Benz A-Class petrol as on other cars the same age.)
6. Any recent work on the washers? (Flagged at MOT 1.7× as often on the 2012 Mercedes-Benz A-Class petrol as on other cars the same age.)