1999 Mercedes-Benz SLK: common problems and MOT failures

What goes wrong more than usual on a 1999 Mercedes-Benz SLK?

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

• Sub-frame2.7× usual
  Mercedes-Benz SLK

  8.3% All 1999 cars

  3.1%

  Failed outright at MOT: 0.1%, against 0.2% of all 1999 cars. The rest were advisories or minor defects.

  Rough price £300–£1,000 our estimate

  At the viewing: Look underneath at the frame the suspension bolts to. Flaky rust or holes are expensive to fix.

• Side repeaters3.9× usual
  Mercedes-Benz SLK

  4.7% All 1999 cars

  1.2%

  Failed outright at MOT: 2.2%, against 0.7% of all 1999 cars. The rest were advisories or minor defects.

  Rough price £10–£80 our estimate

  At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.

• Transmission oil leaks2.7× usual
  Mercedes-Benz SLK

  5.3% All 1999 cars

  2%

  Failed outright at MOT: 0.1%, against 0% 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.

• All direction indicators7× usual
  Mercedes-Benz SLK

  2.8% All 1999 cars

  0.4%

  Failed outright at MOT: 1.9%, against 0.2% of all 1999 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.

• Corroded fuel pipes2.1× usual
  Mercedes-Benz SLK

  2.1% All 1999 cars

  1%

  Failed outright at MOT: 0%, against 0% of all 1999 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.

Common 1999 Mercedes-Benz SLK MOT failures and advisories

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

• Brakes
  34% 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
  33% of testsRough price £10–£80

  At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.

• Suspension
  28% 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
  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.

• Oil and fluid leaks
  11% 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
  10% of testsRough price £15–£250

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

Questions to ask the seller before buying a 1999 Mercedes-Benz SLK

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

1. Any recent work on the sub-frame? (Flagged at MOT 2.7× as often on the 1999 Mercedes-Benz SLK as on other cars the same age.)
2. Any recent work on the side repeaters? (Flagged at MOT 3.9× as often on the 1999 Mercedes-Benz SLK as on other cars the same age.)
3. Any recent work on the transmission oil leaks? (Flagged at MOT 2.7× as often on the 1999 Mercedes-Benz SLK as on other cars the same age.)
4. Can I see the service history and receipts for any big jobs?