2012 Mercedes-Benz SLK: common problems and what to check
What gets flagged at MOT on 2012 Mercedes-Benz SLKs, from 5,482 tests in 2025, plus known faults and what to look at before you buy one.
What stands out
Parts flagged at MOT more often on 2012 Mercedes-Benz SLKs than on all cars registered in 2012.
- Rigid brake pipes2.6× usualMercedes-Benz SLK14.2% All 2012 cars5.5%
Failed outright at MOT: 2%, against 0.8% of all 2012 cars. The rest were advisories or minor defects.
Rough price £100–£400 our estimateAt 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.
- Link ball joint covers2.7× usualMercedes-Benz SLK6.7% All 2012 cars2.5%
Failed outright at MOT: 3.5%, against 1.4% of all 2012 cars. The rest were advisories or minor defects.
Rough price £60–£150 (one joint) ClickMechanicAt the viewing: Listen for knocking over bumps and check the rubber boots behind the wheels aren't split.
- Wheel bearings2.5× usualMercedes-Benz SLK3.8% All 2012 cars1.5%
Failed outright at MOT: 0.1%, against 0.6% of all 2012 cars. The rest were advisories or minor defects.
Rough price £120–£300 (one bearing) ClickMechanicAt the viewing: Listen for a hum or growl that changes as you steer at speed.
- Ball joint dust cover1.8× usualMercedes-Benz SLK5.1% All 2012 cars2.9%
Failed outright at MOT: 2.6%, against 1.2% of all 2012 cars. The rest were advisories or minor defects.
Rough price £60–£150 (one joint) ClickMechanicAt the viewing: Listen for knocking over bumps and check the rubber boots behind the wheels aren't split.
Number plate lights: 0.5% here, against 7.3% of all 2012 cars. Suspension arm bushes and joints: 4.9% here, against 10.1% of all 2012 cars.
By area
The share of 2012 Mercedes-Benz SLK MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.
- Tyres30% 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.
- Brakes28% 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.
- Suspension26% 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 electrics12% 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 leaks5% 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 mirrors5% of testsRough price £15–£250
At the viewing: Check for chips in the driver's view, and test the wipers and washers.
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Other years
| Year | MOT tests | Most flagged |
|---|---|---|
| 2016 | 1,248 | Tyres 31% |
| 2015 | 4,852 | Tyres 30% |
| 2014 | 4,786 | Tyres 31% |
| 2013 | 4,481 | Tyres 31% |
| 2011 | 2,481 | Brakes 30% |
| 2010 | 2,039 | Brakes 31% |
| 2009 | 2,444 | Suspension 33% |
| 2008 | 3,124 | Suspension 35% |
| 2007 | 3,390 | Suspension 37% |
| 2006 | 3,487 | Suspension 36% |
| 2005 | 4,447 | Suspension 36% |
| 2004 | 2,774 | Suspension 38% |
| 2003 | 1,531 | Lights and electrics 35% |
| 2002 | 1,637 | Brakes 35% |
| 2001 | 1,856 | Brakes 33% |
| 2000 | 1,515 | Lights and electrics 35% |
Where this comes from: the DVSA's anonymised results for every MOT test in Great Britain in 2025, counting tests of 2012 Mercedes-Benz SLKs registered in 2012. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score