2015 Audi A3 diesel: common problems and MOT failures

What goes wrong more than usual on a 2015 Audi A3 diesel?

Parts flagged at MOT more often on the 2015 Audi A3 diesel than on all cars registered in 2015.

• Shock absorbers1.7× usual
  Audi A3

  8% All 2015 cars

  4.6%

  Failed outright at MOT: 1.5%, against 0.9% of all 2015 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.

• Engine warning light2.3× usual
  Audi A3

  3.5% All 2015 cars

  1.5%

  Failed outright at MOT: 3.5%, against 1.5% of all 2015 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 2015 Audi A3 diesel MOT failures and advisories

The share of 2015 Audi A3 diesel MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

• Tyres
  33% 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
  23% 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
  16% 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
  8% of testsRough price £10–£80

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

• 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.

• Oil and fluid leaks
  3% 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.

Known faults on the 2015 Audi A3 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.

• S tronic automatic

  S tronic automatic only

  The S tronic gearbox can jerk or hesitate at low speed, usually when its oil changes have been skipped.

  At the viewing: If it’s an automatic, pull away gently from a standstill several times and ask for proof of gearbox servicing.

  Source: Euro Premium Parts: Audi A3 8V reliability guide

• EGR valve and particulate filter (diesel)

  TDI diesel

  Short-trip diesels can clog the EGR valve and particulate filter, causing rough running and limp mode.

  At the viewing: Ask what journeys it’s done and watch for warning lights.

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

  Source: Euro Premium Parts: Audi A3 8V reliability guide

Questions to ask the seller before buying a 2015 Audi A3 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 shock absorbers? (Flagged at MOT 1.7× as often on the 2015 Audi A3 diesel as on other cars the same age.)
2. Any recent work on the engine warning light? (Flagged at MOT 2.3× as often on the 2015 Audi A3 diesel as on other cars the same age.)
3. Can I see the service history and receipts for any big jobs?