Part of the Vauxhall Insignia B (2017–2022) guide: best and worst years compared.
2021 Vauxhall Insignia diesel: common problems and MOT failures
What MOT testers find on the diesel Vauxhall Insignia first registered in 2021 (diesel cars only): we looked at the 1,713 MOTs these cars had during 2023–2025. Plus known faults and what to look at before you buy one.
What goes wrong more than usual on a 2021 Vauxhall Insignia diesel?
Parts flagged at MOT more often on the 2021 Vauxhall Insignia diesel than on all cars registered in 2021.
- Brake pads2.2× usualVauxhall Insignia13.3% All 2021 cars6%
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) ClickMechanicAt the viewing: Listen for squealing or grinding when braking, and look through the wheel at how much pad is left.
- Exhaust system36× usualVauxhall Insignia3.6% All 2021 cars0.1%
Failed outright at MOT: 1.5%, against 0% of all 2021 cars. The rest were advisories or minor defects.
Rough price £100–£500 (pipe or section) ClickMechanicAt the viewing: Listen for blowing or rattling from underneath at idle, and look for black soot around joints.
- Shock absorbers2.2× usualVauxhall Insignia3.1% All 2021 cars1.4%
Failed outright at MOT: 0.1%, against 0.3% of all 2021 cars. The rest were advisories or minor defects.
Rough price £200–£300 (pair, average rear to front) ClickMechanicAt the viewing: Push down hard on each corner. It should bounce once and settle. Look for oil on the shock absorber body.
Common 2021 Vauxhall Insignia diesel MOT failures and advisories
The share of 2021 Vauxhall Insignia diesel MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.
- Tyres23% 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.
- Brakes18% 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 mirrors8% of testsRough price £15–£250
At the viewing: Check for chips in the driver's view, and test the wipers and washers.
- Suspension4% 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.
- Exhaust and emissions4% of testsRough price £100–£1,200
At the viewing: Look for black soot in the tailpipe, listen for blowing from the exhaust and check for engine or DPF warning lights.
- Lights and electrics3% of testsRough price £10–£80
At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.
Questions to ask the seller before buying a 2021 Vauxhall Insignia diesel
Ask before you travel to see it. A seller who knows the car will have answers, and receipts.
- Any recent work on the brake pads? (Flagged at MOT 2.2× as often on the 2021 Vauxhall Insignia diesel as on other cars the same age.)
- Any recent work on the exhaust system? (Flagged at MOT 36× as often on the 2021 Vauxhall Insignia diesel as on other cars the same age.)
- Any recent work on the shock absorbers? (Flagged at MOT 2.2× as often on the 2021 Vauxhall Insignia diesel as on other cars the same age.)
- Can I see the service history and receipts for any big jobs?
Looking at a Vauxhall Insignia?
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 Insignia compared
| Year | MOT tests | Most flagged |
|---|---|---|
| 2022 | 633 | Tyres 39% |
| 2020 | 3,957 | Tyres 26% |
| 2019 | 23,888 | Tyres 29% |
| 2018 | 37,936 | Tyres 30% |
| 2017 | 46,306 | Tyres 32% |
| 2016 | 66,473 | Tyres 34% |
| 2015 | 85,058 | Tyres 36% |
| 2014 | 74,941 | Tyres 36% |
| 2013 | 61,358 | Tyres 37% |
| 2012 | 59,110 | Tyres 39% |
| 2011 | 66,448 | Suspension 40% |
| 2010 | 39,810 | Suspension 43% |
| 2009 | 27,884 | Suspension 47% |
| 2008 | 310 | Suspension 41% |
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 Insignia cars first registered in 2021. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score