2011 Mercedes-Benz B-Class petrol: common problems and MOT failures

What goes wrong more than usual on a 2011 Mercedes-Benz B-Class petrol?

Parts flagged at MOT more often on the 2011 Mercedes-Benz B-Class petrol than on all cars registered in 2011.

• Rigid brake pipes3.3× usual
  Mercedes-Benz B-Class

  19% All 2011 cars

  5.7%

  Failed outright at MOT: 2.9%, against 1% of all 2011 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 repeaters6.3× usual
  Mercedes-Benz B-Class

  7.5% All 2011 cars

  1.2%

  Failed outright at MOT: 6.6%, against 0.8% of all 2011 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.

• Link ball joint covers2.9× usual
  Mercedes-Benz B-Class

  6.9% All 2011 cars

  2.4%

  Failed outright at MOT: 3.2%, against 1.4% of all 2011 cars. The rest were advisories or minor defects.

  Rough price £60–£150 (one joint) ClickMechanic

  At the viewing: Listen for knocking over bumps and check the rubber boots behind the wheels aren't split.

• Individual direction indicators2.5× usual
  Mercedes-Benz B-Class

  7.4% All 2011 cars

  3%

  Failed outright at MOT: 3.5%, against 1.2% of all 2011 cars. The rest were advisories or minor defects.

  Rough price £10–£80 our estimate

  At the viewing: Ask a friend to check every light while you work the switches: indicators, brake lights, fog lights and reversing lights.

• Drive shaft (CV) joints2× usual
  Mercedes-Benz B-Class

  8.2% All 2011 cars

  4.2%

  Failed outright at MOT: 3.5%, against 2% of all 2011 cars. The rest were advisories or minor defects.

  Rough price £60–£350 our estimate

  At the viewing: Drive slowly on full steering lock in both directions and listen for clicking. Look for split rubber boots behind the front wheels.

Common 2011 Mercedes-Benz B-Class petrol MOT failures and advisories

The share of 2011 Mercedes-Benz B-Class petrol MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

• Brakes
  37% 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
  29% 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
  28% 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
  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
  8% of testsRough price £60–£350

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

Questions to ask the seller before buying a 2011 Mercedes-Benz B-Class 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 rigid brake pipes? (Flagged at MOT 3.3× as often on the 2011 Mercedes-Benz B-Class petrol as on other cars the same age.)
2. Any recent work on the side repeaters? (Flagged at MOT 6.3× as often on the 2011 Mercedes-Benz B-Class petrol as on other cars the same age.)
3. Any recent work on the link ball joint covers? (Flagged at MOT 2.9× as often on the 2011 Mercedes-Benz B-Class petrol as on other cars the same age.)
4. Can I see the service history and receipts for any big jobs?