2004 Kia Rio — MOT failures & pass rate
The 2004 Kia Rio passed 68.8% of its 2,733 recorded MOT tests. Against superminis of a similar age (29.1% fail rate), the 2004 Rio comes out 2.1pp worse. Failures cluster in lighting & signalling, suspension and body, structure & corrosion.
What the MOT record shows
No single area dominates — lighting & signalling (17.1%) and suspension (15.5%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp aim, joints and wheel bearings — headlamp aim alone was recorded 292 times.
Condition tracks the odometer closely. Failures run at 15.9% in the 0-30k band and 35.0% in the 120-150k band, a 19.2-point spread — more than double.
Advisories point at the next bill rather than this one: suspension was flagged on 39.0% of tests without failing them.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 17.1% | 467 |
| 2 | Suspension | 15.5% | 424 |
| 3 | Body, structure & corrosion | 12.3% | 337 |
| 4 | Brakes | 11.6% | 318 |
| 5 | Visibility | 8.4% | 229 |
| 6 | Emissions & environmental | 7.0% | 192 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp aim | 292 |
| 2 | Joints | 249 |
| 3 | Wheel bearings | 247 |
| 4 | Headlamp | 216 |
| 5 | Component mounting prescribed areas | 196 |
| 6 | Wipers | 155 |
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 | 39.0% | 1,065 |
| 2 | Brakes | 32.0% | 876 |
| 3 | Tyres | 31.1% | 850 |
| 4 | Emissions & environmental | 27.6% | 755 |
| 5 | Body, structure & corrosion | 20.3% | 554 |
| 6 | Lighting & signalling | 19.7% | 539 |
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 | 145 | 15.9% |
| 30-60k | 917 | 29.7% |
| 60-90k | 1,117 | 33.3% |
| 90-120k | 432 | 33.6% |
| 120-150k | 117 | 35.0% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 883 | 30.1% |
| 2022 | 680 | 32.2% |
| 2023 | 503 | 29.6% |
| 2024 | 408 | 34.8% |
| 2025 | 259 | 30.1% |
What to check before buying a 2004 Rio
On a 2004 Rio, lighting & signalling is what the MOT record says goes wrong most — it appeared in 17.1% of tests. Check these areas before you commit.
- Lighting & signalling (17.1% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (15.5% 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.
- Body, structure & corrosion (12.3% 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 2004 Kia Rios pass their MOT?
68.8% of the 2,733 2004 Kia Rio MOT tests in this dataset passed — a 31.3% fail rate.
What is the most common MOT failure on a 2004 Kia Rio?
Lighting & signalling, recorded in 17.1% of tests, followed by suspension (15.5%).
Does the 2004 Rio get worse with mileage?
Its MOT fail rate rises from 15.9% in the 0-30k band to 35.0% in the 120-150k band.
Methodology & source. Based on 2,733 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.