Used car guide

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

What gets flagged at MOT on 2009 Mercedes-Benz CLKs, from 2,745 tests in 2025, plus known faults and what to look at before you buy one.

2,745MOT tests in 2025
61%pass first time (all 2009 cars: 58%)
6,000typical miles a year
3.2×the usual rate for rigid brake pipes

What stands out

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

  • Rigid brake pipes3.2× usual
    Mercedes-Benz CLK
    23.9% All 2009 cars
    7.5%

    Failed outright at MOT: 2.8%, 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.

  • Ball joint2.4× usual
    Mercedes-Benz CLK
    16.1% All 2009 cars
    6.6%

    Failed outright at MOT: 9%, against 3.4% of all 2009 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.

  • Wheel bearings3.9× usual
    Mercedes-Benz CLK
    8.5% All 2009 cars
    2.2%

    Failed outright at MOT: 0.4%, against 0.8% of all 2009 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.

  • Anti-roll bar bushes and joints5× usual
    Mercedes-Benz CLK
    4% All 2009 cars
    0.8%

    Failed outright at MOT: 1.1%, against 0.2% of all 2009 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.

  • Anti-roll bar link bushes4.1× usual
    Mercedes-Benz CLK
    3.3% All 2009 cars
    0.8%

    Failed outright at MOT: 1.2%, against 0.2% of all 2009 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.

Better than most

Number plate lights: 3.1% here, against 8.8% of all 2009 cars. Engine oil leaks: 4.8% here, against 10.4% of all 2009 cars.

By area

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

  • Suspension
    46% 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
    44% 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
    31% 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
    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.

  • Exhaust and emissions
    12% 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.

  • Wipers, windscreen and mirrors
    10% 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 CLK?

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Other years

YearMOT testsMost flagged
20082,454Suspension 48%
20073,399Suspension 50%
20062,832Suspension 47%
20053,419Suspension 48%
20043,442Suspension 49%
20032,433Suspension 45%
20021,331Brakes 42%
20011,121Brakes 37%
2000949Brakes 40%

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