Used car guide

2009 Mercedes-Benz S-Class: common problems and what to check

What gets flagged at MOT on 2009 Mercedes-Benz S-Classs, from 753 tests in 2025, plus known faults and what to look at before you buy one.

753MOT tests in 2025
72%pass first time (all 2009 cars: 58%)
6,900typical miles a year
2.3×the usual rate for rigid brake pipes

What stands out

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

  • Rigid brake pipes2.3× usual
    Mercedes-Benz S-Class
    17.3% All 2009 cars
    7.5%

    Failed outright at MOT: 2%, 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.

  • Wheel bearings3.5× usual
    Mercedes-Benz S-Class
    7.7% All 2009 cars
    2.2%

    Failed outright at MOT: 0.7%, 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.

  • Flexible couplings40× usual
    Mercedes-Benz S-Class
    4% All 2009 cars
    0.1%

    Failed outright at MOT: 0.3%, against 0% of all 2009 cars. The rest were advisories or minor defects.

    Rough price £150–£1,000 our estimate

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

Better than most

Shock absorbers: 3.2% here, against 7.5% of all 2009 cars. Braking performance: 2.8% here, against 6.4% of all 2009 cars.

By area

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

  • Brakes
    37% 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
    25% 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
    24% 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.

  • Lights and electrics
    20% 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
    17% 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 S-Class?

Check the actual car: its own MOT history, mileage and what to ask the seller. Free, no sign-up.

Other years

YearMOT testsMost flagged
20192,195Tyres 19%
20182,177Tyres 19%
20172,265Tyres 21%
20162,634Tyres 24%
20152,124Tyres 23%
20141,572Tyres 21%
2013946Brakes 27%
20121,148Brakes 33%
2011883Brakes 32%
2010773Brakes 32%
2008810Brakes 40%
20071,127Brakes 39%
2006883Brakes 38%
2004521Brakes 35%
2003522Brakes 34%

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