2008 Mercedes-Benz ML diesel: common problems and MOT failures

What goes wrong more than usual on a 2008 Mercedes-Benz ML diesel?

Parts flagged at MOT more often on the 2008 Mercedes-Benz ML diesel than on all cars registered in 2008.

• Engine oil leaks2.5× usual
  Mercedes-Benz ML

  28.1% All 2008 cars

  11.2%

  Failed outright at MOT: 1.1%, against 0.3% of all 2008 cars. The rest were advisories or minor defects.

  Rough price £80–£600 our estimate

  At the viewing: Look under the engine and where the car is usually parked for fresh oil. Ask whether the leak has been looked at.

• Rigid brake pipes2.3× usual
  Mercedes-Benz ML

  21.6% All 2008 cars

  9.3%

  Failed outright at MOT: 3.6%, against 1.7% of all 2008 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.

• Handbrake cables10.3× usual
  Mercedes-Benz ML

  3.1% All 2008 cars

  0.3%

  Failed outright at MOT: 0.5%, against 0.1% of all 2008 cars. The rest were advisories or minor defects.

  Rough price £80–£300 our estimate

  At the viewing: Pull the handbrake on a slope. It should hold the car within a few clicks.

• Side repeaters2.1× usual
  Mercedes-Benz ML

  2.9% All 2008 cars

  1.4%

  Failed outright at MOT: 1.8%, against 0.9% of all 2008 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.

Common 2008 Mercedes-Benz ML diesel MOT failures and advisories

The share of 2008 Mercedes-Benz ML diesel MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

• Brakes
  40% 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
  30% of testsRough price £10–£80

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

• Oil and fluid leaks
  30% 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.

• Suspension
  30% 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.

• Tyres
  28% 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.

• 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 2008 Mercedes-Benz ML 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 engine oil leaks? (Flagged at MOT 2.5× as often on the 2008 Mercedes-Benz ML diesel as on other cars the same age.)
2. Any recent work on the rigid brake pipes? (Flagged at MOT 2.3× as often on the 2008 Mercedes-Benz ML diesel as on other cars the same age.)
3. Any recent work on the handbrake cables? (Flagged at MOT 10.3× as often on the 2008 Mercedes-Benz ML diesel as on other cars the same age.)
4. Can I see the service history and receipts for any big jobs?