Used car guide

2009 Mercedes-Benz ML: common problems and what to check

What gets flagged at MOT on 2009 Mercedes-Benz MLs, from 1,745 tests in 2025, plus known faults and what to look at before you buy one.

1,745MOT tests in 2025
67%pass first time (all 2009 cars: 58%)
7,800typical miles a year
2.6×the usual rate for engine oil leaks

What stands out

Parts flagged at MOT more often on 2009 Mercedes-Benz MLs than on all cars registered in 2009.

  • Engine oil leaks2.6× usual
    Mercedes-Benz ML
    27.3% All 2009 cars
    10.4%

    Failed outright at MOT: 1.3%, against 0.3% of all 2009 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 pipes2.7× usual
    Mercedes-Benz ML
    20.1% All 2009 cars
    7.5%

    Failed outright at MOT: 2.5%, against 1.2% of all 2009 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 repeaters5.5× usual
    Mercedes-Benz ML
    8.3% All 2009 cars
    1.5%

    Failed outright at MOT: 6.1%, against 0.9% of all 2009 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.

  • Handbrake cables16× usual
    Mercedes-Benz ML
    3.2% All 2009 cars
    0.2%

    Failed outright at MOT: 0.5%, against 0.1% of all 2009 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.

  • Diesel smoke emissions2.8× usual
    Mercedes-Benz ML
    2.5% All 2009 cars
    0.9%

    Failed outright at MOT: 1.8%, against 0.8% of all 2009 cars. The rest were advisories or minor defects.

    Rough price £175–£900 (catalytic converter) ClickMechanic

    At the viewing: Look for smoke when revving the warm engine and for engine or DPF warning lights.

Better than most

Exhaust system: 1.1% here, against 8.4% of all 2009 cars. Ball joint: 1.6% here, against 6.6% of all 2009 cars.

By area

The share of 2009 Mercedes-Benz ML MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Brakes
    38% 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
    32% of testsRough price £10–£80

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

  • 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.

  • Oil and fluid leaks
    29% 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.

  • Wipers, windscreen and mirrors
    8% of testsRough price £15–£250

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

Looking at a Mercedes-Benz ML?

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Other years

YearMOT testsMost flagged
20153,138Tyres 28%
20143,787Tyres 28%
20134,070Tyres 27%
20122,218Tyres 27%
20112,383Tyres 29%
20102,340Brakes 31%
20081,886Brakes 38%
20071,710Brakes 39%
20061,376Brakes 38%
2005771Suspension 49%
20041,006Suspension 55%
2003755Suspension 54%
2002653Suspension 51%

Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2009 Mercedes-Benz MLs registered in 2009. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score