1997 Mercedes-Benz SL: common problems and MOT failures

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

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

• Ball joint dust cover2.6× usual
  Mercedes-Benz SL

  8.4% All 1997 cars

  3.2%

  Failed outright at MOT: 1.9%, against 1% of all 1997 cars. The rest were advisories or minor defects.

  Rough price £60–£150 (one joint) ClickMechanic

  At the viewing: Listen for knocking over bumps and check the rubber boots behind the wheels aren't split.

• Sub-frame2.4× usual
  Mercedes-Benz SL

  6.3% All 1997 cars

  2.6%

  Failed outright at MOT: 0.1%, 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.

• Side repeaters3.3× usual
  Mercedes-Benz SL

  3.9% All 1997 cars

  1.2%

  Failed outright at MOT: 2.1%, against 0.9% 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, including brake lights and indicators, while you operate them.

• Corroded fuel pipes2.3× usual
  Mercedes-Benz SL

  2.3% All 1997 cars

  1%

  Failed outright at MOT: 0%, against 0% of all 1997 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 1997 Mercedes-Benz SL MOT failures and advisories

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

• Brakes
  26% 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
  25% 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
  19% 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.

• Tyres
  16% 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.

• Wipers, windscreen and mirrors
  6% 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 SL

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

1. Any recent work on the ball joint dust cover? (Flagged at MOT 2.6× as often on the 1997 Mercedes-Benz SL as on other cars the same age.)
2. Any recent work on the sub-frame? (Flagged at MOT 2.4× as often on the 1997 Mercedes-Benz SL as on other cars the same age.)
3. Any recent work on the side repeaters? (Flagged at MOT 3.3× as often on the 1997 Mercedes-Benz SL as on other cars the same age.)
4. Can I see the service history and receipts for any big jobs?