Vauxhall Signum MOT pass rate & common failures
Across 10 model years and 11,685 tests, the Vauxhall Signum passes its MOT 70.7% of the time. Against large family cars of a similar age (27.3% fail rate), the Signum comes out 1.9pp worse. Its most common failure areas are suspension, lighting & signalling and brakes.
Best and worst Signum years
Ranked across Signum years with at least 1,000 tests. Older cars fail more simply because they are older — compare years close together in age before drawing conclusions.
What the MOT record shows
Not every year is equal — 72.0% of 2006 examples pass against 67.4% of 2004 ones.
No single area dominates — suspension (14.8%) and lighting & signalling (14.1%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are coil spring, rigid brake pipes and headlamp aim — coil spring alone was recorded 827 times.
Mileage is the strongest signal on the record: 15.7% of 0-30k cars fail, rising to 30.0% once past 150k.
Fuel type barely separates them — petrol fails 29.2% of the time against 29.3% for diesel.
Brakes is the most common advisory, noted on 39.3% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 29.7% in 2021 to 27.9% in 2025, as the worst-kept examples leave the fleet.
How it compares
By model year
Every Signum model year with a usable sample. Years with their own detailed report are linked.
| Year | Tests | Pass rate | Fail rate | Most common failure |
|---|---|---|---|---|
| 2003 | 568 | 70.3% | 29.8% | Brakes |
| 2004 | 1,708 | 67.4% | 32.6% | Suspension |
| 2005 | 2,341 | 70.4% | 29.6% | Lighting & signalling |
| 2006 | 4,154 | 72.0% | 28.0% | Suspension |
| 2007 | 2,635 | 71.4% | 28.6% | Suspension |
| 2008 | 229 | 68.6% | 31.4% | Suspension |
| 2011 | 32 | 75.0% | 25.0% | Lighting & signalling |
Most common failures (all years)
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Suspension | 14.8% | 1,732 |
| 2 | Lighting & signalling | 14.1% | 1,652 |
| 3 | Brakes | 12.8% | 1,492 |
| 4 | Body, structure & corrosion | 8.0% | 929 |
| 5 | Tyres | 7.3% | 848 |
| 6 | Emissions & environmental | 5.9% | 683 |
| 7 | Visibility | 5.1% | 596 |
| 8 | Steering | 1.6% | 185 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Coil spring | 827 |
| 2 | Rigid brake pipes | 780 |
| 3 | Headlamp aim | 770 |
| 4 | Headlamp | 570 |
| 5 | Joints | 558 |
| 6 | Exhaust system | 444 |
| 7 | Tread depth | 439 |
| 8 | Position lamp | 405 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Brakes | 39.3% | 4,594 |
| 2 | Suspension | 32.9% | 3,849 |
| 3 | Tyres | 30.4% | 3,556 |
| 4 | Body, structure & corrosion | 20.3% | 2,368 |
| 5 | Lighting & signalling | 18.8% | 2,192 |
| 6 | Other defects | 17.1% | 1,997 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 0-30k | 51 | 15.7% |
| 30-60k | 598 | 23.4% |
| 60-90k | 1,947 | 26.4% |
| 90-120k | 3,208 | 29.5% |
| 120-150k | 3,189 | 31.3% |
| 150k+ | 2,655 | 30.0% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Diesel | 7,302 | 29.3% |
| Petrol | 4,383 | 29.2% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 3,934 | 29.7% |
| 2022 | 2,895 | 29.5% |
| 2023 | 2,205 | 29.3% |
| 2024 | 1,525 | 28.7% |
| 2025 | 1,126 | 27.9% |
What to check before buying a Vauxhall Signum
- Suspension (14.8% of tests): Worn drop links, bushes, springs or shocks — listen for knocks over bumps and check for uneven tyre wear. Typical repair: £150–£450 per corner.
- Lighting & signalling (14.1% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (12.8% of tests): Pads/discs are routine wear; binding, imbalance or corroded pipes are more serious — test for pulling under braking. Typical repair: £100–£350 per axle.
Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.
Frequently asked questions
What is the MOT pass rate for the Vauxhall Signum?
70.7% of the 11,685 Vauxhall Signum MOT tests in this dataset passed, a 29.3% fail rate, across model years 2003–2012.
What does the Vauxhall Signum most often fail its MOT on?
Suspension, recorded in 14.8% of tests, then lighting & signalling (14.1%).
Which Signum years are best and worst for MOT results?
2006 has the best pass rate at 72.0% and 2004 the weakest at 67.4%, from 4,154 and 1,708 tests respectively.
How much does mileage affect Signum MOT results?
Fail rates run at 15.7% for cars in the 0-30k band and 30.0% for 150k+, a 14.3-point difference.
Is the petrol or diesel Signum more reliable at MOT time?
On MOT-testable defects the petrol fails 29.2% of the time against 29.3% for the diesel. This covers testable items only, not engine or gearbox reliability.
Methodology & source. Based on 11,685 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-27. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.