1990 Ford Sierra — MOT failures & pass rate
The 1990 Ford Sierra passed 87.9% of its 1,810 recorded MOT tests. Against large family cars of a similar age (14.3% fail rate), the 1990 Sierra comes out 2.2pp better. Failures cluster in lighting & signalling, suspension and body, structure & corrosion.
What the MOT record shows
No single area dominates — lighting & signalling (5.9%) and suspension (4.9%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are component mounting prescribed areas, headlamp aim and integral vehicle structure condition — component mounting prescribed areas alone was recorded 95 times.
Mileage matters less than usual here: the 1990 Sierra fails 13.0% of the time in the 0-30k band and 10.3% at 90-120k, a spread of only 2.7 points.
Suspension is the most common advisory, noted on 13.0% of tests — work that passed today but is likely due soon.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 5.9% | 106 |
| 2 | Suspension | 4.9% | 88 |
| 3 | Body, structure & corrosion | 4.0% | 73 |
| 4 | Brakes | 3.6% | 65 |
| 5 | Emissions & environmental | 3.3% | 59 |
| 6 | Visibility | 1.9% | 35 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Component mounting prescribed areas | 95 |
| 2 | Headlamp aim | 56 |
| 3 | Integral vehicle structure condition | 47 |
| 4 | Non catalyst emissions | 44 |
| 5 | Prescribed areas | 33 |
| 6 | Joints | 28 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Suspension | 13.0% | 235 |
| 2 | Brakes | 12.5% | 227 |
| 3 | Emissions & environmental | 11.5% | 208 |
| 4 | Body, structure & corrosion | 10.7% | 194 |
| 5 | Tyres | 9.1% | 165 |
| 6 | Other defects | 5.9% | 107 |
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 | 591 | 13.0% |
| 30-60k | 503 | 12.3% |
| 60-90k | 485 | 11.6% |
| 90-120k | 214 | 10.3% |
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 1,773 | 12.0% |
| Diesel | 37 | 18.9% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 383 | 12.5% |
| 2022 | 392 | 13.8% |
| 2023 | 363 | 12.7% |
| 2024 | 331 | 10.0% |
| 2025 | 341 | 11.1% |
What to check before buying a 1990 Sierra
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 5.9% of tests. Start there.
- Lighting & signalling (5.9% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (4.9% 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.
- Body, structure & corrosion (4.0% of tests): The one to take seriously on older cars — corrosion to structural areas can be costly and is an MOT failure. Typical repair: £200–£1,500+.
Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.
Frequently asked questions
How many 1990 Ford Sierras pass their MOT?
87.9% of the 1,810 1990 Ford Sierra MOT tests in this dataset passed — a 12.1% fail rate.
What is the most common MOT failure on a 1990 Ford Sierra?
Lighting & signalling, recorded in 5.9% of tests, followed by suspension (4.9%).
Does the 1990 Sierra get worse with mileage?
Its MOT fail rate rises from 13.0% in the 0-30k band to 10.3% in the 90-120k band.
Methodology & source. Based on 1,810 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.