2005 Mercedes-Benz CLK diesel: common problems and MOT failures

What goes wrong more than usual on a 2005 Mercedes-Benz CLK diesel?

Parts flagged at MOT more often on the 2005 Mercedes-Benz CLK diesel than on all cars registered in 2005.

• Ball joint3× usual
  Mercedes-Benz CLK

  19.7% All 2005 cars

  6.5%

  Failed outright at MOT: 10.6%, against 3.2% of all 2005 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.

• Rigid brake pipes1.8× usual
  Mercedes-Benz CLK

  26.7% All 2005 cars

  14.9%

  Failed outright at MOT: 3.3%, against 2.6% of all 2005 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.

• Wheel bearings2.5× usual
  Mercedes-Benz CLK

  9% All 2005 cars

  3.6%

  Failed outright at MOT: 1.1%, against 1.4% of all 2005 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.

• Anti-roll bar bushes and joints3.6× usual
  Mercedes-Benz CLK

  5.4% All 2005 cars

  1.5%

  Failed outright at MOT: 1%, against 0.3% of all 2005 cars. The rest were advisories or minor defects.

  Rough price £100–£280 (pair of drop links) Checkatrade

  At the viewing: Drive slowly over bumps and listen for a knock or rattle from the front. Worn anti-roll bar links are a cheap fix.

• Diesel smoke emissions4.9× usual
  Mercedes-Benz CLK

  4.4% All 2005 cars

  0.9%

  Failed outright at MOT: 4%, against 0.8% of all 2005 cars. The rest were advisories or minor defects.

  Rough price £175–£900 (catalytic converter) ClickMechanic

  At the viewing: Look for smoke when revving the warm engine and for engine or DPF warning lights.

Common 2005 Mercedes-Benz CLK diesel MOT failures and advisories

The share of 2005 Mercedes-Benz CLK diesel MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

• Suspension
  56% 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.

• Brakes
  48% 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
  39% of testsRough price £10–£80

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

• Tyres
  35% 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.

• Exhaust and emissions
  13% 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
  11% 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 2005 Mercedes-Benz CLK diesel

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? (Flagged at MOT 3× as often on the 2005 Mercedes-Benz CLK diesel as on other cars the same age.)
2. Any recent work on the rigid brake pipes? (Flagged at MOT 1.8× as often on the 2005 Mercedes-Benz CLK diesel as on other cars the same age.)
3. Any recent work on the wheel bearings? (Flagged at MOT 2.5× as often on the 2005 Mercedes-Benz CLK diesel as on other cars the same age.)
4. Can I see the service history and receipts for any big jobs?