Used car guide

1999 Mercedes-Benz ML: common problems and what to check

What gets flagged at MOT on 1999 Mercedes-Benz MLs, from 164 tests in 2025, plus known faults and what to look at before you buy one.

Small sample: only 164 of these were MOT tested in 2025, so treat the percentages as rough. The known faults below don't depend on it.

164MOT tests in 2025
63%pass first time (all 1999 cars: 65%)
5,000typical miles a year
3.1×the usual rate for engine oil leaks

What stands out

Parts flagged at MOT more often on 1999 Mercedes-Benz MLs than on all cars registered in 1999.

  • Engine oil leaks3.1× usual
    Mercedes-Benz ML
    48.8% All 1999 cars
    15.7%

    Failed outright at MOT: 0.6%, against 0.3% of all 1999 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.

  • Headlights4.3× usual
    Mercedes-Benz ML
    25.6% All 1999 cars
    5.9%

    Failed outright at MOT: 7.9%, against 2.8% of all 1999 cars. The rest were advisories or minor defects.

    Rough price £40–£400 our estimate

    At the viewing: Check both headlights on dipped and full beam, and look for cloudy or cracked lenses.

By area

The share of 1999 Mercedes-Benz ML MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Oil and fluid leaks
    52% 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
    51% 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
    45% 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
    44% 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
    32% 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.

  • Rust and bodywork
    18% of testsRough price £150–£1,000

    At the viewing: Check the sills, wheel arches and underneath for rust, and look along the panels for uneven gaps or paint.

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%
20091,745Brakes 38%
20081,886Brakes 38%
20071,710Brakes 39%
20061,376Suspension 38%
2005771Suspension 49%
20041,006Suspension 55%
2003755Suspension 54%
2002653Suspension 51%
2001377Suspension 46%
2000318Brakes 49%

Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 1999 Mercedes-Benz MLs registered in 1999. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score