1985 Jaguar XJ — MOT failures & pass rate
294 MOT tests on the 1985 Jaguar XJ are in this dataset, and 85.0% of them passed. Executive cars of a similar age fail 17.3% of the time, so this is 2.4pp better than the group it competes with. Failures cluster in brakes, lighting & signalling and suspension.
What the MOT record shows
No single area dominates — brakes (8.2%) and lighting & signalling (8.2%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are ball joint dust cover, rbt (sp) and headlamp aim — ball joint dust cover alone was recorded 17 times.
A 90-120k example is materially riskier than a 0-30k one: 21.4% versus 9.4%.
Advisories point at the next bill rather than this one: suspension was flagged on 20.1% of tests without failing them.
The trend is improving — the fail rate fell from 18.5% 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 | Brakes | 8.2% | 24 |
| 2 | Lighting & signalling | 8.2% | 24 |
| 3 | Suspension | 5.4% | 16 |
| 4 | Body, structure & corrosion | 4.1% | 12 |
| 5 | Visibility | 3.1% | 9 |
| 6 | Emissions & environmental | 2.0% | 6 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Ball joint dust cover | 17 |
| 2 | Rbt (sp) | 14 |
| 3 | Headlamp aim | 9 |
| 4 | Headlamp | 9 |
| 5 | Service brake performance | 9 |
| 6 | Component mounting prescribed areas | 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 | 20.1% | 59 |
| 2 | Emissions & environmental | 15.7% | 46 |
| 3 | Body, structure & corrosion | 11.6% | 34 |
| 4 | Brakes | 9.9% | 29 |
| 5 | Tyres | 8.2% | 24 |
| 6 | Steering | 5.8% | 17 |
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 | 32 | 9.4% |
| 30-60k | 74 | 9.5% |
| 60-90k | 90 | 13.3% |
| 90-120k | 70 | 21.4% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 65 | 18.5% |
| 2022 | 63 | 11.1% |
| 2023 | 69 | 21.7% |
| 2024 | 55 | 10.9% |
| 2025 | 42 | 9.5% |
What to check before buying a 1985 XJ
On a 1985 XJ, brakes is what the MOT record says goes wrong most — it appeared in 8.2% of tests. Check these areas before you commit.
- Brakes (8.2% 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.
- Lighting & signalling (8.2% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (5.4% 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 1985 Jaguar XJs pass their MOT?
85.0% of the 294 1985 Jaguar XJ MOT tests in this dataset passed — a 15.0% fail rate.
What is the most common MOT failure on a 1985 Jaguar XJ?
Brakes, recorded in 8.2% of tests, followed by lighting & signalling (8.2%).
Does the 1985 XJ get worse with mileage?
Its MOT fail rate rises from 9.4% in the 0-30k band to 21.4% in the 90-120k band.
Methodology & source. Based on 294 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.