1989 Ford Sierra — MOT failures & pass rate
Across 1,732 MOT tests, the 1989 Ford Sierra recorded an 87.2% pass rate. That is effectively the same as large family cars of a similar age (13.1% fail rate), so the MOT record here is unremarkable in either direction. Failures cluster in lighting & signalling, suspension and body, structure & corrosion.
What the MOT record shows
No single area dominates — lighting & signalling (6.9%) and suspension (4.6%) 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 and non catalyst emissions — component mounting prescribed areas alone was recorded 80 times.
Mileage matters less than usual here: the 1989 Sierra fails 13.2% of the time in the 0-30k band and 11.6% at 90-120k, a spread of only 1.6 points.
Brakes is the most common advisory, noted on 13.2% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 11.9% in 2021 to 9.1% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 6.9% | 119 |
| 2 | Suspension | 4.6% | 80 |
| 3 | Body, structure & corrosion | 4.6% | 79 |
| 4 | Brakes | 4.5% | 77 |
| 5 | Emissions & environmental | 3.4% | 58 |
| 6 | Visibility | 3.2% | 55 |
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 | 80 |
| 2 | Headlamp | 66 |
| 3 | Non catalyst emissions | 50 |
| 4 | Headlamp aim | 46 |
| 5 | Prescribed areas | 36 |
| 6 | Wipers | 35 |
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 | 13.2% | 229 |
| 2 | Suspension | 13.2% | 229 |
| 3 | Emissions & environmental | 11.9% | 206 |
| 4 | Body, structure & corrosion | 10.6% | 184 |
| 5 | Tyres | 7.2% | 125 |
| 6 | Other defects | 5.9% | 102 |
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 | 532 | 13.2% |
| 30-60k | 439 | 14.8% |
| 60-90k | 520 | 11.5% |
| 90-120k | 225 | 11.6% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 386 | 11.9% |
| 2022 | 369 | 16.0% |
| 2023 | 343 | 11.9% |
| 2024 | 325 | 14.5% |
| 2025 | 309 | 9.1% |
What to check before buying a 1989 Sierra
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 6.9% of tests. Start there.
- Lighting & signalling (6.9% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (4.6% 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 (4.6% 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 1989 Ford Sierras pass their MOT?
87.2% of the 1,732 1989 Ford Sierra MOT tests in this dataset passed — a 12.8% fail rate.
What is the most common MOT failure on a 1989 Ford Sierra?
Lighting & signalling, recorded in 6.9% of tests, followed by suspension (4.6%).
Does the 1989 Sierra get worse with mileage?
Its MOT fail rate rises from 13.2% in the 0-30k band to 11.6% in the 90-120k band.
Methodology & source. Based on 1,732 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.