1988 Ford Sierra — MOT failures & pass rate
The 1988 Ford Sierra passed 87.7% of its 1,107 recorded MOT tests. Large family cars of a similar age fail at 11.8%, so the 1988 Sierra sits squarely on the average. Failures cluster in lighting & signalling, emissions & environmental and suspension.
What the MOT record shows
No single area dominates — lighting & signalling (5.4%) and emissions & environmental (5.1%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are non catalyst emissions, component mounting prescribed areas and integral vehicle structure condition — non catalyst emissions alone was recorded 44 times.
Mileage matters less than usual here: the 1988 Sierra fails 11.0% of the time in the 0-30k band and 12.3% at 90-120k, a spread of only 1.3 points.
Advisories point at the next bill rather than this one: brakes was flagged on 13.3% of tests without failing them.
The trend is improving — the fail rate fell from 14.8% in 2021 to 9.5% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 5.4% | 60 |
| 2 | Emissions & environmental | 5.1% | 56 |
| 3 | Suspension | 4.5% | 50 |
| 4 | Brakes | 3.8% | 42 |
| 5 | Body, structure & corrosion | 3.6% | 40 |
| 6 | Steering | 2.5% | 28 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Non catalyst emissions | 44 |
| 2 | Component mounting prescribed areas | 34 |
| 3 | Integral vehicle structure condition | 27 |
| 4 | Steering rack | 26 |
| 5 | Headlamp aim | 24 |
| 6 | Position lamp | 20 |
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 | 13.3% | 147 |
| 2 | Suspension | 12.2% | 135 |
| 3 | Body, structure & corrosion | 9.4% | 104 |
| 4 | Emissions & environmental | 9.2% | 102 |
| 5 | Tyres | 7.8% | 86 |
| 6 | Other defects | 6.4% | 71 |
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 | 327 | 11.0% |
| 30-60k | 280 | 13.9% |
| 60-90k | 323 | 12.4% |
| 90-120k | 171 | 12.3% |
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 1,077 | 12.1% |
| Diesel | 30 | 20.0% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 229 | 14.8% |
| 2022 | 224 | 13.4% |
| 2023 | 212 | 10.8% |
| 2024 | 221 | 12.7% |
| 2025 | 221 | 9.5% |
What to check before buying a 1988 Sierra
On a 1988 Sierra, lighting & signalling is what the MOT record says goes wrong most — it appeared in 5.4% of tests. Check these areas before you commit.
- Lighting & signalling (5.4% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Emissions & environmental (5.1% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
- Suspension (4.5% 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 1988 Ford Sierras pass their MOT?
87.7% of the 1,107 1988 Ford Sierra MOT tests in this dataset passed — a 12.3% fail rate.
What is the most common MOT failure on a 1988 Ford Sierra?
Lighting & signalling, recorded in 5.4% of tests, followed by emissions & environmental (5.1%).
Does the 1988 Sierra get worse with mileage?
Its MOT fail rate rises from 11.0% in the 0-30k band to 12.3% in the 90-120k band.
Methodology & source. Based on 1,107 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.