2006 Vauxhall Signum diesel: common problems and MOT failures

What goes wrong more than usual on a 2006 Vauxhall Signum diesel?

Parts flagged at MOT more often on the 2006 Vauxhall Signum diesel than on all cars registered in 2006.

• Exhaust system2.1× usual
  Vauxhall Signum

  19.7% All 2006 cars

  9.2%

  Failed outright at MOT: 3.4%, against 2.6% of all 2006 cars. The rest were advisories or minor defects.

  Rough price £100–£500 (pipe or section) ClickMechanic

  At the viewing: Listen for blowing or rattling from underneath at idle, and look for black soot around joints.

• Coil springs1.9× usual
  Vauxhall Signum

  20.3% All 2006 cars

  10.5%

  Failed outright at MOT: 6.8%, against 3.3% of all 2006 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.

• Sub-frame1.9× usual
  Vauxhall Signum

  10.3% All 2006 cars

  5.5%

  Failed outright at MOT: 0.3%, against 0.3% of all 2006 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.

• Anti-roll bar link joints2.1× usual
  Vauxhall Signum

  9% All 2006 cars

  4.3%

  Failed outright at MOT: 3.4%, against 1.6% of all 2006 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.

• Diesel smoke emissions4× usual
  Vauxhall Signum

  3.6% All 2006 cars

  0.9%

  Failed outright at MOT: 3.5%, against 0.8% of all 2006 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 2006 Vauxhall Signum diesel MOT failures and advisories

The share of 2006 Vauxhall Signum diesel MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

• Suspension
  53% 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.

• Tyres
  41% 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
  35% 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
  22% 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.

• Oil and fluid leaks
  14% 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.

Questions to ask the seller before buying a 2006 Vauxhall Signum 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 exhaust system? (Flagged at MOT 2.1× as often on the 2006 Vauxhall Signum diesel as on other cars the same age.)
2. Any recent work on the coil springs? (Flagged at MOT 1.9× as often on the 2006 Vauxhall Signum diesel as on other cars the same age.)
3. Any recent work on the sub-frame? (Flagged at MOT 1.9× as often on the 2006 Vauxhall Signum diesel as on other cars the same age.)
4. Can I see the service history and receipts for any big jobs?