1999 Jaguar XJ — MOT failures & pass rate
2,670 MOT tests on the 1999 Jaguar XJ are in this dataset, and 75.2% of them passed. Against executive cars of a similar age (23.2% fail rate), the 1999 XJ comes out 1.6pp worse. Failures cluster in emissions & environmental, suspension and lighting & signalling.
What the MOT record shows
No single area dominates — emissions & environmental (11.6%) and suspension (10.0%) 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 integral vehicle structure condition — catalyst emissions alone was recorded 532 times.
Condition tracks the odometer closely. Failures run at 14.5% in the 0-30k band and 31.8% in the 150k+ band, a 17.2-point spread — more than double.
Suspension is the most common advisory, noted on 39.9% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 25.8% in 2021 to 23.8% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Emissions & environmental | 11.6% | 309 |
| 2 | Suspension | 10.0% | 266 |
| 3 | Lighting & signalling | 7.9% | 212 |
| 4 | Brakes | 7.4% | 197 |
| 5 | Body, structure & corrosion | 7.3% | 195 |
| 6 | Visibility | 4.4% | 118 |
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 | 532 |
| 2 | Component mounting prescribed areas | 297 |
| 3 | Integral vehicle structure condition | 147 |
| 4 | Chassis condition | 125 |
| 5 | Prescribed areas | 96 |
| 6 | Headlamp aim | 91 |
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 | 39.9% | 1,064 |
| 2 | Brakes | 23.9% | 639 |
| 3 | Tyres | 21.2% | 566 |
| 4 | Body, structure & corrosion | 17.2% | 459 |
| 5 | Other defects | 12.0% | 321 |
| 6 | Emissions & environmental | 8.8% | 234 |
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 | 55 | 14.5% |
| 30-60k | 430 | 20.9% |
| 60-90k | 852 | 22.5% |
| 90-120k | 808 | 26.5% |
| 120-150k | 396 | 29.3% |
| 150k+ | 126 | 31.8% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 681 | 25.8% |
| 2022 | 623 | 27.0% |
| 2023 | 509 | 23.2% |
| 2024 | 457 | 23.2% |
| 2025 | 400 | 23.8% |
What to check before buying a 1999 XJ
The failure pattern for this year is specific enough to inspect against: emissions & environmental accounted for 11.6% of tests. Start there.
- Emissions & environmental (11.6% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
- Suspension (10.0% 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.
- Lighting & signalling (7.9% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
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 1999 Jaguar XJs pass their MOT?
75.2% of the 2,670 1999 Jaguar XJ MOT tests in this dataset passed — a 24.8% fail rate.
What is the most common MOT failure on a 1999 Jaguar XJ?
Emissions & environmental, recorded in 11.6% of tests, followed by suspension (10.0%).
Does the 1999 XJ get worse with mileage?
Its MOT fail rate rises from 14.5% in the 0-30k band to 31.8% in the 150k+ band.
Methodology & source. Based on 2,670 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.