2009 Mercedes-Benz SLK: common problems and MOT failures

What goes wrong more than usual on a 2009 Mercedes-Benz SLK?

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

• Rigid brake pipes2.2× usual
  Mercedes-Benz SLK

  16.1% All 2009 cars

  7.2%

  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.

• Individual direction indicators1.8× usual
  Mercedes-Benz SLK

  5.2% All 2009 cars

  2.9%

  Failed outright at MOT: 1.4%, against 1.3% 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 while you work the switches: indicators, brake lights, fog lights and reversing lights.

• Wheel bearings1.9× usual
  Mercedes-Benz SLK

  4% All 2009 cars

  2.1%

  Failed outright at MOT: 0.2%, 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.

Common 2009 Mercedes-Benz SLK MOT failures and advisories

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

• Brakes
  30% 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.

• Suspension
  30% 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.

• Tyres
  29% 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
  21% 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
  7% 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
  7% of testsRough price £15–£250

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

Known faults on the 2009 Mercedes-Benz SLK

Reported by owners, mechanics and buying guides for this model and age. Check which engine the car has, as some apply to one engine only.

• Roof motors and pump

  All engines

  The roof motors can seize if the roof stays up for long periods, and a slow roof usually means a failing pump. Both are costly.

  At the viewing: Open and close the roof several times and time it.

  Source: What Car?: used Mercedes-Benz SLK (2004-2011) reliability

• Leaking boot seals

  All engines

  Boot seals fail often, letting water collect in the spare wheel well.

  At the viewing: Lift the boot floor and look for water or damp.

  Source: What Car?: used Mercedes-Benz SLK (2004-2011) reliability

Questions to ask the seller before buying a 2009 Mercedes-Benz SLK

Ask before you travel to see it. A seller who knows the car will have answers, and receipts.

1. Has the roof had any work?
2. Any recent work on the rigid brake pipes? (Flagged at MOT 2.2× as often on the 2009 Mercedes-Benz SLK as on other cars the same age.)
3. Any recent work on the individual direction indicators? (Flagged at MOT 1.8× as often on the 2009 Mercedes-Benz SLK as on other cars the same age.)
4. Any recent work on the wheel bearings? (Flagged at MOT 1.9× as often on the 2009 Mercedes-Benz SLK as on other cars the same age.)
5. Can I see the service history and receipts for any big jobs?