2004 Daihatsu Sirion — MOT failures & pass rate
766 MOT tests on the 2004 Daihatsu Sirion are in this dataset, and 73.1% of them passed. That is 2.7 percentage points better than city cars of a similar age, which fail at 29.5%. Failures cluster in lighting & signalling, suspension and emissions & environmental.
What the MOT record shows
No single area dominates — lighting & signalling (13.8%) and suspension (12.0%) 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, malfunction indicator lamp and wipers — component mounting prescribed areas alone was recorded 112 times.
Condition tracks the odometer closely. Failures run at 20.4% in the 0-30k band and 31.8% in the 90-120k band, a 11.3-point spread.
Advisories point at the next bill rather than this one: suspension was flagged on 30.2% of tests without failing them.
The trend is worsening — 26.8% of tests failed in 2021 against 31.7% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 13.8% | 106 |
| 2 | Suspension | 12.0% | 92 |
| 3 | Emissions & environmental | 11.2% | 86 |
| 4 | Brakes | 8.9% | 68 |
| 5 | Body, structure & corrosion | 7.4% | 57 |
| 6 | Visibility | 5.9% | 45 |
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 | 112 |
| 2 | Malfunction indicator lamp | 51 |
| 3 | Wipers | 40 |
| 4 | Headlamp aim | 40 |
| 5 | Position lamp | 31 |
| 6 | Exhaust system | 30 |
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 | 30.2% | 231 |
| 2 | Brakes | 28.1% | 215 |
| 3 | Tyres | 23.2% | 178 |
| 4 | Other defects | 15.5% | 119 |
| 5 | Body, structure & corrosion | 14.8% | 113 |
| 6 | Lighting & signalling | 10.6% | 81 |
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 | 44 | 20.4% |
| 30-60k | 292 | 25.7% |
| 60-90k | 256 | 27.3% |
| 90-120k | 129 | 31.8% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 220 | 26.8% |
| 2022 | 168 | 25.6% |
| 2023 | 145 | 22.1% |
| 2024 | 129 | 30.2% |
| 2025 | 104 | 31.7% |
What to check before buying a 2004 Sirion
On a 2004 Sirion, lighting & signalling is what the MOT record says goes wrong most — it appeared in 13.8% of tests. Check these areas before you commit.
- Lighting & signalling (13.8% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (12.0% 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.
- Emissions & environmental (11.2% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
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 2004 Daihatsu Sirions pass their MOT?
73.1% of the 766 2004 Daihatsu Sirion MOT tests in this dataset passed — a 26.9% fail rate.
What is the most common MOT failure on a 2004 Daihatsu Sirion?
Lighting & signalling, recorded in 13.8% of tests, followed by suspension (12.0%).
Does the 2004 Sirion get worse with mileage?
Its MOT fail rate rises from 20.4% in the 0-30k band to 31.8% in the 90-120k band.
Methodology & source. Based on 766 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.