Used car guide

2021 Vauxhall Astra diesel: common problems and MOT failures

What MOT testers find on the diesel Vauxhall Astra first registered in 2021 (diesel cars only): we looked at the 2,484 MOTs these cars had during 2023–2025. Plus known faults and what to look at before you buy one.

2,484MOTs of 2021 diesel cars, done in 2023–2025
85%pass first time (all 2021 cars: 87%)
11,400typical miles a year
2.2×the usual rate for brake pads

What goes wrong more than usual on a 2021 Vauxhall Astra diesel?

Parts flagged at MOT more often on the 2021 Vauxhall Astra diesel than on all cars registered in 2021.

  • Brake pads2.2× usual
    Vauxhall Astra
    13.2% All 2021 cars
    6.1%

    Failed outright at MOT: 2.9%, against 1.1% of all 2021 cars. The rest were advisories or minor defects.

    Rough price £75–£175 (one axle) ClickMechanic

    At the viewing: Listen for squealing or grinding when braking, and look through the wheel at how much pad is left.

Common 2021 Vauxhall Astra diesel MOT failures and advisories

The share of 2021 Vauxhall Astra diesel MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Tyres
    25% 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
    18% 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.

  • Wipers, windscreen and mirrors
    5% of testsRough price £15–£250

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

  • Lights and electrics
    5% of testsRough price £10–£80

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

  • Suspension
    2% 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.

  • Oil and fluid leaks
    1% 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 2021 Vauxhall Astra 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.

  • Brief loss of power with a metallic noise

    1.0 petrol and 1.6 diesel

    The 1.0 petrol and 1.6 diesel can briefly lose power with a metallic noise. On diesels, a faulty oil pressure sensor is one cause.

    At the viewing: Drive it for 20 minutes or more. Any sudden dips in power or engine warning lights are a reason to ask questions.

    Source: Haynes: Vauxhall Astra K common problems

  • Exhaust smell in the cabin (diesel)

    Diesel

    A badly fitted clamp between the particulate filter and turbo can let exhaust fumes into the cabin.

    At the viewing: Sit in the car with the engine running and the fan on. Any exhaust smell needs fixing before you buy.

    Source: Haynes: Vauxhall Astra K common problems

  • Front suspension creak

    A worn lower arm bush makes a creak over speed bumps.

    At the viewing: Drive slowly over a speed bump and listen at the front.

    Source: Haynes: Vauxhall Astra K common problems

Questions to ask the seller before buying a 2021 Vauxhall Astra 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 brake pads? (Flagged at MOT 2.2× as often on the 2021 Vauxhall Astra diesel as on other cars the same age.)
  2. Can I see the service history and receipts for any big jobs?

Looking at a Vauxhall Astra?

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 Vauxhall Astra compared

YearMOT testsMost flagged
2026–Too new for MOT data
2025–Too new for MOT data
2024–Too new for MOT data
2023217Tyres 12%
20222,966Tyres 25%
202018,903Tyres 22%
201962,909Tyres 26%
201889,577Tyres 30%
2017137,261Tyres 32%
2016167,049Tyres 33%
2015140,327Tyres 34%
2014154,957Tyres 35%
2013171,024Tyres 36%
2012150,456Tyres 36%
2011131,828Tyres 37%
2010147,017Suspension 41%
2009109,313Suspension 48%
2008110,932Suspension 49%
2007109,840Suspension 50%
200668,175Suspension 53%
200545,866Suspension 52%
200424,837Brakes 49%
200322,533Brakes 51%
200217,225Brakes 53%
20019,770Brakes 51%
20005,239Brakes 51%
19993,204Brakes 47%
19981,654Brakes 44%
19971,588Suspension 44%
1996877Suspension 47%
19951,013Suspension 42%
1994666Suspension 37%
1993501Suspension 33%
1992233Suspension 24%
1991321Brakes 21%
1990348Suspension 18%
1989–Too few tests
1988–Too few tests
1987–Too few tests
1986–Too few tests
1985–Too few tests
1984–Too few tests
1983–Too few tests
1982–Too few tests
1981–Too few tests

Where this comes from: the DVSA's anonymised results for every MOT test done in Great Britain during 2023–2025, counting the MOTs of Vauxhall Astra cars first registered in 2021. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score