2008 Audi A4 diesel: common problems and MOT failures

What goes wrong more than usual on a 2008 Audi A4 diesel?

Parts flagged at MOT more often on the 2008 Audi A4 diesel than on all cars registered in 2008.

• Suspension arm bushes and joints2× usual
  Audi A4

  21.2% All 2008 cars

  10.7%

  Failed outright at MOT: 2.5%, against 2.3% of all 2008 cars. The rest were advisories or minor defects.

  Rough price £120–£180 (one arm) ClickMechanic

  At the viewing: Listen for clunks over bumps and feel for the steering wandering. Worn arm bushes show as cracked rubber near the wheels.

• Drive shaft (CV) joints2× usual
  Audi A4

  13.6% All 2008 cars

  6.7%

  Failed outright at MOT: 6.3%, against 3% of all 2008 cars. The rest were advisories or minor defects.

  Rough price £60–£350 our estimate

  At the viewing: Drive slowly on full steering lock in both directions and listen for clicking. Look for split rubber boots behind the front wheels.

• Anti-roll bar link bushes4.1× usual
  Audi A4

  3.7% All 2008 cars

  0.9%

  Failed outright at MOT: 1.1%, against 0.2% of all 2008 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.

• Engine warning light1.7× usual
  Audi A4

  4.5% All 2008 cars

  2.6%

  Failed outright at MOT: 4.5%, against 2.6% of all 2008 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 2008 Audi A4 diesel MOT failures and advisories

The share of 2008 Audi A4 diesel MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

• Suspension
  49% 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
  36% 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.

• Brakes
  29% 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
  25% of testsRough price £10–£80

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

• Driveshafts and joints
  14% of testsRough price £60–£350

  At the viewing: On full steering lock, drive slowly and listen for clicking from the front wheels.

• 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.

Known faults on the 2008 Audi A4 diesel

Reported by owners, mechanics and buying guides for this model and age. Check which engine the car has, as some apply to one engine only.

• EGR and particulate filter (diesel)

  2.0 TDI diesel

  Diesels can clog the EGR valve and particulate filter, especially with short trips.

  At the viewing: Watch for black smoke, rough idle or warning lights.

  If it needs doing: DPF clean or regeneration, about £160–£500. ClickMechanic

  Source: Euro Premium Parts: Audi A4 B8 reliability guide

• Worn front suspension bushes

  Front control arm bushes wear early, causing clunks and vague steering.

  At the viewing: Listen over bumps and feel for wander.

  Source: Euro Premium Parts: Audi A4 B8 reliability guide

Questions to ask the seller before buying a 2008 Audi A4 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 suspension arm bushes and joints? (Flagged at MOT 2× as often on the 2008 Audi A4 diesel as on other cars the same age.)
2. Any recent work on the drive shaft (cv) joints? (Flagged at MOT 2× as often on the 2008 Audi A4 diesel as on other cars the same age.)
3. Any recent work on the anti-roll bar link bushes? (Flagged at MOT 4.1× as often on the 2008 Audi A4 diesel as on other cars the same age.)
4. Can I see the service history and receipts for any big jobs?