1997 Mercedes-Benz SLK: common problems and MOT failures

What goes wrong more than usual on a 1997 Mercedes-Benz SLK?

Parts flagged at MOT more often on the 1997 Mercedes-Benz SLK than on all cars registered in 1997.

• Sub-frame3.9× usual
  Mercedes-Benz SLK

  10.1% All 1997 cars

  2.6%

  Failed outright at MOT: 0%, against 0.1% of all 1997 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.

• Transmission oil leaks4.2× usual
  Mercedes-Benz SLK

  9.2% All 1997 cars

  2.2%

  Failed outright at MOT: 0.1%, against 0.1% of all 1997 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.

• Headlights2.5× usual
  Mercedes-Benz SLK

  10.6% All 1997 cars

  4.3%

  Failed outright at MOT: 4.1%, against 2.5% of all 1997 cars. The rest were advisories or minor defects.

  Rough price £40–£400 our estimate

  At the viewing: Check both headlights on dipped and full beam, and look for cloudy or cracked lenses.

• Coil springs1.8× usual
  Mercedes-Benz SLK

  12% All 1997 cars

  6.7%

  Failed outright at MOT: 1.1%, against 0.9% of all 1997 cars. The rest were advisories or minor defects.

  Rough price £175–£400 (pair, one axle) ClickMechanic

  At the viewing: Look behind each wheel for a snapped spring coil, and listen for a clunk or twang when turning the wheel lock to lock with the car stopped.

• Brake lights2.2× usual
  Mercedes-Benz SLK

  8.5% All 1997 cars

  3.8%

  Failed outright at MOT: 7.5%, against 3.1% of all 1997 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.

Common 1997 Mercedes-Benz SLK MOT failures and advisories

The share of 1997 Mercedes-Benz SLK MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

• Lights and electrics
  36% of testsRough price £10–£80

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

• Brakes
  33% 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
  32% 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
  24% 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
  16% 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 1997 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 3.9× as often on the 1997 Mercedes-Benz SLK as on other cars the same age.)
2. Any recent work on the transmission oil leaks? (Flagged at MOT 4.2× as often on the 1997 Mercedes-Benz SLK as on other cars the same age.)
3. Any recent work on the headlights? (Flagged at MOT 2.5× as often on the 1997 Mercedes-Benz SLK as on other cars the same age.)
4. Can I see the service history and receipts for any big jobs?