1984 Jaguar Xjs — MOT failures & pass rate
320 MOT tests on the 1984 Jaguar Xjs are in this dataset, and 80.6% of them passed. All cars of a similar age fail at 19.7%, so the 1984 Xjs sits squarely on the average. Failures cluster in lighting & signalling, brakes and visibility.
What the MOT record shows
No single area dominates — lighting & signalling (10.6%) and brakes (7.8%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are washers, headlamp aim and service brake performance — washers alone was recorded 19 times.
Mileage is the strongest signal on the record: 19.3% of 0-30k cars fail, rising to 24.6% once past 90-120k.
Advisories point at the next bill rather than this one: suspension was flagged on 28.1% of tests without failing them.
The trend is improving — the fail rate fell from 21.8% in 2021 to 16.7% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 10.6% | 34 |
| 2 | Brakes | 7.8% | 25 |
| 3 | Visibility | 7.5% | 24 |
| 4 | Suspension | 5.0% | 16 |
| 5 | Body, structure & corrosion | 4.1% | 13 |
| 6 | Emissions & environmental | 4.1% | 13 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Washers | 19 |
| 2 | Headlamp aim | 17 |
| 3 | Service brake performance | 16 |
| 4 | Non catalyst emissions | 11 |
| 5 | Headlamp | 10 |
| 6 | Rbt (sp) | 9 |
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 | 28.1% | 90 |
| 2 | Emissions & environmental | 18.4% | 59 |
| 3 | Brakes | 11.6% | 37 |
| 4 | Tyres | 8.4% | 27 |
| 5 | Body, structure & corrosion | 7.8% | 25 |
| 6 | Steering | 4.7% | 15 |
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 | 57 | 19.3% |
| 30-60k | 70 | 24.3% |
| 60-90k | 107 | 15.9% |
| 90-120k | 61 | 24.6% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 87 | 21.8% |
| 2022 | 85 | 24.7% |
| 2023 | 72 | 15.3% |
| 2024 | 46 | 13.0% |
| 2025 | 30 | 16.7% |
What to check before buying a 1984 Xjs
On a 1984 Xjs, lighting & signalling is what the MOT record says goes wrong most — it appeared in 10.6% of tests. Check these areas before you commit.
- Lighting & signalling (10.6% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (7.8% of tests): Pads/discs are routine wear; binding, imbalance or corroded pipes are more serious — test for pulling under braking. Typical repair: £100–£350 per axle.
- Visibility (7.5% of tests): Wipers, washers, mirrors and screen damage — usually inexpensive, but check for chips in the driver's line of sight. Typical repair: £15–£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 1984 Jaguar Xjss pass their MOT?
80.6% of the 320 1984 Jaguar Xjs MOT tests in this dataset passed — a 19.4% fail rate.
What is the most common MOT failure on a 1984 Jaguar Xjs?
Lighting & signalling, recorded in 10.6% of tests, followed by brakes (7.8%).
Does the 1984 Xjs get worse with mileage?
Its MOT fail rate rises from 19.3% in the 0-30k band to 24.6% in the 90-120k band.
Methodology & source. Based on 320 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.