1993 Ford Sierra — MOT failures & pass rate
Across 546 MOT tests, the 1993 Ford Sierra recorded an 85.2% pass rate. That is 6.0 percentage points better than large family cars of a similar age, which fail at 20.8%. Failures cluster in lighting & signalling, emissions & environmental and suspension.
What the MOT record shows
No single area dominates — lighting & signalling (8.6%) and emissions & environmental (7.1%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are catalyst emissions, component mounting prescribed areas and headlamp — catalyst emissions alone was recorded 55 times.
Condition tracks the odometer closely. Failures run at 16.5% in the 0-30k band and 5.3% in the 90-120k band, a 11.2-point spread.
Advisories point at the next bill rather than this one: brakes was flagged on 14.5% of tests without failing them.
The trend is worsening — 14.8% of tests failed in 2021 against 16.5% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 8.6% | 47 |
| 2 | Emissions & environmental | 7.1% | 39 |
| 3 | Suspension | 5.3% | 29 |
| 4 | Body, structure & corrosion | 3.7% | 20 |
| 5 | Brakes | 3.5% | 19 |
| 6 | Visibility | 2.8% | 15 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Catalyst emissions | 55 |
| 2 | Component mounting prescribed areas | 30 |
| 3 | Headlamp | 15 |
| 4 | Pins and bushes | 15 |
| 5 | Headlamp aim | 15 |
| 6 | Position lamp | 12 |
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 | 14.5% | 79 |
| 2 | Suspension | 13.7% | 75 |
| 3 | Tyres | 10.4% | 57 |
| 4 | Emissions & environmental | 10.3% | 56 |
| 5 | Other defects | 10.3% | 56 |
| 6 | Body, structure & corrosion | 6.6% | 36 |
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 | 133 | 16.5% |
| 30-60k | 158 | 14.6% |
| 60-90k | 176 | 18.2% |
| 90-120k | 75 | 5.3% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 128 | 14.8% |
| 2022 | 120 | 19.2% |
| 2023 | 110 | 10.9% |
| 2024 | 91 | 12.1% |
| 2025 | 97 | 16.5% |
What to check before buying a 1993 Sierra
On a 1993 Sierra, lighting & signalling is what the MOT record says goes wrong most — it appeared in 8.6% of tests. Check these areas before you commit.
- Lighting & signalling (8.6% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Emissions & environmental (7.1% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
- Suspension (5.3% 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.
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 1993 Ford Sierras pass their MOT?
85.2% of the 546 1993 Ford Sierra MOT tests in this dataset passed — a 14.8% fail rate.
What is the most common MOT failure on a 1993 Ford Sierra?
Lighting & signalling, recorded in 8.6% of tests, followed by emissions & environmental (7.1%).
Does the 1993 Sierra get worse with mileage?
Its MOT fail rate rises from 16.5% in the 0-30k band to 5.3% in the 90-120k band.
Methodology & source. Based on 546 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.