1998 BMW Z3 — MOT failures & pass rate
The 1998 BMW Z3 passed 75.9% of its 15,985 recorded MOT tests. That is 2.6 percentage points worse than coupes & convertibles of a similar age, which fail at 21.6%. Failures cluster in lighting & signalling, emissions & environmental and brakes.
What the MOT record shows
No single area dominates — lighting & signalling (9.9%) and emissions & environmental (9.6%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are catalyst emissions, rigid brake pipes and headlamp aim — catalyst emissions alone was recorded 2,138 times.
A 150k+ example is materially riskier than a 0-30k one: 31.4% versus 9.5%.
Brakes is the most common advisory, noted on 35.4% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 26.1% in 2021 to 22.0% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 9.9% | 1,580 |
| 2 | Emissions & environmental | 9.6% | 1,530 |
| 3 | Brakes | 9.6% | 1,527 |
| 4 | Suspension | 9.0% | 1,445 |
| 5 | Visibility | 5.1% | 821 |
| 6 | Body, structure & corrosion | 3.5% | 559 |
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 | 2,138 |
| 2 | Rigid brake pipes | 697 |
| 3 | Headlamp aim | 695 |
| 4 | Position lamp | 586 |
| 5 | Washers | 519 |
| 6 | SRS malfunction indicator lamp | 480 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Brakes | 35.4% | 5,665 |
| 2 | Suspension | 29.2% | 4,661 |
| 3 | Tyres | 18.2% | 2,905 |
| 4 | Emissions & environmental | 11.9% | 1,908 |
| 5 | Body, structure & corrosion | 11.3% | 1,806 |
| 6 | Other defects | 10.2% | 1,626 |
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 | 766 | 9.5% |
| 30-60k | 2,673 | 16.1% |
| 60-90k | 5,031 | 23.1% |
| 90-120k | 4,545 | 27.7% |
| 120-150k | 2,276 | 31.3% |
| 150k+ | 644 | 31.4% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 3,571 | 26.1% |
| 2022 | 3,523 | 25.2% |
| 2023 | 3,228 | 23.9% |
| 2024 | 2,919 | 22.6% |
| 2025 | 2,744 | 22.0% |
What to check before buying a 1998 Z3
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 9.9% of tests. Start there.
- Lighting & signalling (9.9% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Emissions & environmental (9.6% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
- Brakes (9.6% 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.
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 1998 BMW Z3s pass their MOT?
75.9% of the 15,985 1998 BMW Z3 MOT tests in this dataset passed — a 24.1% fail rate.
What is the most common MOT failure on a 1998 BMW Z3?
Lighting & signalling, recorded in 9.9% of tests, followed by emissions & environmental (9.6%).
Does the 1998 Z3 get worse with mileage?
Its MOT fail rate rises from 9.5% in the 0-30k band to 31.4% in the 150k+ band.
Methodology & source. Based on 15,985 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.