Used car guide

2018 Audi A1 diesel: common problems and MOT failures

What MOT testers find on the diesel Audi A1 first registered in 2018 (diesel cars only): we looked at the 3,115 MOTs these cars had during 2023–2025. Plus known faults and what to look at before you buy one.

3,115MOTs of 2018 diesel cars, done in 2023–2025
80%pass first time (all 2018 cars: 83%)
8,800typical miles a year
5.1×the usual rate for suspension arm bushes and joints

What goes wrong more than usual on a 2018 Audi A1 diesel?

Parts flagged at MOT more often on the 2018 Audi A1 diesel than on all cars registered in 2018.

  • Suspension arm bushes and joints5.1× usual
    Audi A1
    11.7% All 2018 cars
    2.3%

    Failed outright at MOT: 4.5%, against 0.4% of all 2018 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.

  • Coil springs1.9× usual
    Audi A1
    2.1% All 2018 cars
    1.1%

    Failed outright at MOT: 1.7%, against 0.8% of all 2018 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.

Common 2018 Audi A1 diesel MOT failures and advisories

The share of 2018 Audi A1 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
    20% 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
    6% 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
    4% of testsRough price £15–£250

    At the viewing: Check for chips in the driver's view, and test the wipers and washers.

  • Seats and seatbelts
    2% of testsRough price £80–£250

    At the viewing: Pull each seatbelt sharply. It should lock, and retract cleanly.

Known faults on the 2018 Audi A1 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.

  • Blocked DPF and rising oil (1.6 TDI)

    1.6 TDI diesel

    The 1.6 diesel's particulate filter needs high-speed runs to clean itself. Interrupted cleaning can also put fuel into the oil, so the oil level rises.

    At the viewing: Ask how the car is used, and check the dipstick: oil above the top mark or smelling of diesel is a bad sign.

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

    Source: What Car?: used Audi A1 2010-2018 advice

  • Bluetooth and small electrical faults

    All engines

    Phone pairing can drop out and there are some niggly electrical faults.

    At the viewing: Pair your own phone on the test drive.

    Source: What Car?: used Audi A1 2010-2018 advice

  • Kerbed alloys

    All engines

    A1s spend a lot of time in towns, so kerbed or cracked wheels are common.

    At the viewing: Check each wheel rim for scuffs and cracks.

    Source: What Car?: used Audi A1 2010-2018 advice

Questions to ask the seller before buying a 2018 Audi A1 diesel

Ask before you travel to see it. A seller who knows the car will have answers, and receipts.

  1. Has it done regular motorway runs, and has the DPF been cleaned?
  2. Have there been any electrical faults?
  3. Have the wheels been refurbished?
  4. Any recent work on the suspension arm bushes and joints? (Flagged at MOT 5.1× as often on the 2018 Audi A1 diesel as on other cars the same age.)
  5. Any recent work on the coil springs? (Flagged at MOT 1.9× as often on the 2018 Audi A1 diesel as on other cars the same age.)
  6. Can I see the service history and receipts for any big jobs?

Looking at an Audi A1?

Check the actual car: its own MOT history, mileage and what to ask the seller. Free, no sign-up.

Other years

Every year of the Audi A1 compared

YearMOT testsMost flagged
2026–Too new for MOT data
2025–Too new for MOT data
2024–Too new for MOT data
2023984Tyres 16%
202215,755Tyres 26%
202128,674Tyres 29%
202039,764Tyres 27%
201960,535Tyres 29%
201768,163Tyres 33%
201675,827Tyres 33%
201570,503Tyres 33%
201468,304Tyres 34%
201366,272Tyres 35%
201254,835Tyres 35%
201148,250Suspension 39%
20104,170Suspension 43%

Where this comes from: the DVSA's anonymised results for every MOT test done in Great Britain during 2023–2025, counting the MOTs of Audi A1 cars first registered in 2018. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score