2006 Mercedes-Benz C-Class diesel: common problems and MOT failures

What goes wrong more than usual on a 2006 Mercedes-Benz C-Class diesel?

Parts flagged at MOT more often on the 2006 Mercedes-Benz C-Class diesel than on all cars registered in 2006.

• Ball joint3.3× usual
  Mercedes-Benz C-Class

  21.3% All 2006 cars

  6.4%

  Failed outright at MOT: 11.7%, against 3.1% of all 2006 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.

• Rigid brake pipes1.8× usual
  Mercedes-Benz C-Class

  25.5% All 2006 cars

  14%

  Failed outright at MOT: 3.2%, against 2.5% of all 2006 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 springs1.8× usual
  Mercedes-Benz C-Class

  18.7% All 2006 cars

  10.6%

  Failed outright at MOT: 6.5%, against 3.2% of all 2006 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.

• Anti-roll bar bushes and joints7× usual
  Mercedes-Benz C-Class

  8.4% All 2006 cars

  1.2%

  Failed outright at MOT: 2.5%, against 0.3% of all 2006 cars. The rest were advisories or minor defects.

  Rough price £100–£280 (pair of drop links) Checkatrade

  At the viewing: Drive slowly over bumps and listen for a knock or rattle from the front. Worn anti-roll bar links are a cheap fix.

• Wheel bearings2.9× usual
  Mercedes-Benz C-Class

  9.2% All 2006 cars

  3.2%

  Failed outright at MOT: 1%, against 1.3% of all 2006 cars. The rest were advisories or minor defects.

  Rough price £120–£300 (one bearing) ClickMechanic

  At the viewing: Listen for a hum or growl that changes as you steer at speed.

Common 2006 Mercedes-Benz C-Class diesel MOT failures and advisories

The share of 2006 Mercedes-Benz C-Class diesel MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

• Suspension
  60% 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.

• Brakes
  47% 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
  35% 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
  34% 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
  12% of testsRough price £15–£250

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

• Exhaust and emissions
  8% of testsRough price £100–£1,200

  At the viewing: Look for black soot in the tailpipe, listen for blowing from the exhaust and check for engine or DPF warning lights.

Questions to ask the seller before buying a 2006 Mercedes-Benz C-Class diesel

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

1. Any recent work on the ball joint? (Flagged at MOT 3.3× as often on the 2006 Mercedes-Benz C-Class diesel as on other cars the same age.)
2. Any recent work on the rigid brake pipes? (Flagged at MOT 1.8× as often on the 2006 Mercedes-Benz C-Class diesel as on other cars the same age.)
3. Any recent work on the coil springs? (Flagged at MOT 1.8× as often on the 2006 Mercedes-Benz C-Class diesel as on other cars the same age.)
4. Can I see the service history and receipts for any big jobs?