2005 Audi A4 diesel: common problems and MOT failures

What goes wrong more than usual on a 2005 Audi A4 diesel?

Parts flagged at MOT more often on the 2005 Audi A4 diesel than on all cars registered in 2005.

• Suspension arm bushes and joints2.1× usual
  Audi A4

  21.8% All 2005 cars

  10.5%

  Failed outright at MOT: 4.1%, against 2.4% of all 2005 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.

• Shock absorbers2.1× usual
  Audi A4

  14% All 2005 cars

  6.7%

  Failed outright at MOT: 2.4%, against 1.7% of all 2005 cars. The rest were advisories or minor defects.

  Rough price £200–£300 (pair, average rear to front) ClickMechanic

  At the viewing: Push down hard on each corner. It should bounce once and settle. Look for oil on the shock absorber body.

• Anti-roll bar link bushes5.1× usual
  Audi A4

  8.6% All 2005 cars

  1.7%

  Failed outright at MOT: 2.6%, against 0.4% 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.

• Number plate lights1.9× usual
  Audi A4

  14.9% All 2005 cars

  7.9%

  Failed outright at MOT: 3.4%, against 2.3% of all 2005 cars. The rest were advisories or minor defects.

  Rough price £5–£40 our estimate

  At the viewing: Check the number plate lights work and the plates are clean and legal.

• Flexible brake hoses1.9× usual
  Audi A4

  10.7% All 2005 cars

  5.6%

  Failed outright at MOT: 3.4%, against 1.2% of all 2005 cars. The rest were advisories or minor defects.

  Rough price £50–£200 our estimate

  At the viewing: Look for cracked or bulging rubber hoses behind the wheels and in the engine bay.

Common 2005 Audi A4 diesel MOT failures and advisories

The share of 2005 Audi A4 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
  38% 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
  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.

• 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.

• Oil and fluid leaks
  15% 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
  11% 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 2005 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.

• Air conditioning faults

  All engines

  There are many reports of air conditioning faults on this A4.

  At the viewing: Turn the air con to its coldest setting and make sure it blows properly cold within a few minutes.

  Source: What Car?: Audi A4 (2000-2005) advice

• Gearbox synchromesh wear

  Manual gearbox

  Some manual gearboxes have synchromesh problems.

  At the viewing: Change up and down through every gear, quickly and slowly. Be wary of crunching or gears that are hard to select.

  Source: What Car?: Audi A4 (2000-2005) advice

• Front suspension wear

  All engines

  A few higher-mileage cars have front suspension problems.

  At the viewing: Listen for knocks or clonks over bumps, and check the steering feels tight.

  Source: What Car?: Audi A4 (2000-2005) advice

• Oil use (diesel)

  Diesel

  Diesels often use a lot of oil when new. It should settle down, but an owner who didn't keep it topped up may have caused damage.

  At the viewing: Check the oil level and ask how often it needs topping up.

  Source: What Car?: Audi A4 (2000-2005) advice

Questions to ask the seller before buying a 2005 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 2.1× as often on the 2005 Audi A4 diesel as on other cars the same age.)
2. Any recent work on the shock absorbers? (Flagged at MOT 2.1× as often on the 2005 Audi A4 diesel as on other cars the same age.)
3. Any recent work on the anti-roll bar link bushes? (Flagged at MOT 5.1× as often on the 2005 Audi A4 diesel as on other cars the same age.)
4. Can I see the service history and receipts for any big jobs?