2004 Mercedes-Benz ML diesel: common problems and MOT failures

What goes wrong more than usual on a 2004 Mercedes-Benz ML diesel?

Parts flagged at MOT more often on the 2004 Mercedes-Benz ML diesel than on all cars registered in 2004.

• Engine oil leaks2.3× usual
  Mercedes-Benz ML

  32.7% All 2004 cars

  14.5%

  Failed outright at MOT: 0.5%, against 0.4% of all 2004 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.

• Anti-roll bar bushes and joints8.2× usual
  Mercedes-Benz ML

  13.9% All 2004 cars

  1.7%

  Failed outright at MOT: 3.7%, against 0.4% of all 2004 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.

• Ball joint2.6× usual
  Mercedes-Benz ML

  17.5% All 2004 cars

  6.7%

  Failed outright at MOT: 4.9%, against 3.2% of all 2004 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.

• Track rod ends2.4× usual
  Mercedes-Benz ML

  15.3% All 2004 cars

  6.5%

  Failed outright at MOT: 8.3%, against 3% of all 2004 cars. The rest were advisories or minor defects.

  Rough price £50–£150 (one end, plus about £30–£50 if it needs a wheel alignment) ClickMechanic

  At the viewing: On a straight road the steering wheel should sit straight. Listen for knocks when turning, and check the steering feels even.

• Brake pads2.2× usual
  Mercedes-Benz ML

  16.2% All 2004 cars

  7.5%

  Failed outright at MOT: 3.2%, against 1.9% of all 2004 cars. The rest were advisories or minor defects.

  Rough price £75–£175 (one axle) ClickMechanic

  At the viewing: Listen for squealing or grinding when braking, and look through the wheel at how much pad is left.

Common 2004 Mercedes-Benz ML diesel MOT failures and advisories

The share of 2004 Mercedes-Benz ML diesel MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

• Suspension
  56% 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
  48% 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
  45% 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
  35% 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.

• Tyres
  27% 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.

• Steering
  14% of testsRough price £100–£450

  At the viewing: On a straight road the steering wheel should sit straight. Feel for play or knocking when turning.

Questions to ask the seller before buying a 2004 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 2.3× as often on the 2004 Mercedes-Benz ML diesel as on other cars the same age.)
2. Any recent work on the anti-roll bar bushes and joints? (Flagged at MOT 8.2× as often on the 2004 Mercedes-Benz ML diesel as on other cars the same age.)
3. Any recent work on the ball joint? (Flagged at MOT 2.6× as often on the 2004 Mercedes-Benz ML diesel as on other cars the same age.)
4. Can I see the service history and receipts for any big jobs?