1998 Audi A4 — MOT failures & pass rate
3,744 MOT tests on the 1998 Audi A4 are in this dataset, and 75.6% of them passed. Against executive cars of a similar age (22.8% fail rate), the 1998 A4 comes out 1.6pp worse. Failures cluster in suspension, lighting & signalling and body, structure & corrosion.
What the MOT record shows
No single area dominates — suspension (13.0%) and lighting & signalling (10.7%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are ball joint, joints and catalyst emissions — ball joint alone was recorded 257 times.
Mileage is the strongest signal on the record: 10.7% of 30-60k cars fail, rising to 26.2% once past 150k — 2.5× the risk.
Fuel type barely separates them — petrol fails 24.3% of the time against 24.5% for diesel.
Advisories point at the next bill rather than this one: suspension was flagged on 39.4% of tests without failing them.
The trend is improving — the fail rate fell from 27.9% in 2021 to 23.7% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Suspension | 13.0% | 487 |
| 2 | Lighting & signalling | 10.7% | 399 |
| 3 | Body, structure & corrosion | 8.6% | 323 |
| 4 | Brakes | 7.5% | 280 |
| 5 | Emissions & environmental | 4.8% | 181 |
| 6 | Steering | 4.5% | 169 |
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 | 257 |
| 2 | Joints | 244 |
| 3 | Catalyst emissions | 202 |
| 4 | Headlamp aim | 184 |
| 5 | Pins and bushes | 140 |
| 6 | Track rod end | 134 |
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 | 39.4% | 1,474 |
| 2 | Brakes | 34.5% | 1,293 |
| 3 | Emissions & environmental | 23.5% | 881 |
| 4 | Tyres | 22.7% | 848 |
| 5 | Body, structure & corrosion | 16.0% | 600 |
| 6 | Lighting & signalling | 12.7% | 476 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 30-60k | 131 | 10.7% |
| 60-90k | 302 | 19.5% |
| 90-120k | 620 | 23.5% |
| 120-150k | 782 | 25.2% |
| 150k+ | 1,896 | 26.2% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 2,321 | 24.3% |
| Diesel | 1,423 | 24.5% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 1,105 | 27.9% |
| 2022 | 892 | 23.1% |
| 2023 | 714 | 22.7% |
| 2024 | 568 | 22.5% |
| 2025 | 465 | 23.7% |
What to check before buying a 1998 A4
On a 1998 A4, suspension is what the MOT record says goes wrong most — it appeared in 13.0% of tests. Check these areas before you commit.
- Suspension (13.0% 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 (10.7% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Body, structure & corrosion (8.6% 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 1998 Audi A4s pass their MOT?
75.6% of the 3,744 1998 Audi A4 MOT tests in this dataset passed — a 24.4% fail rate.
What is the most common MOT failure on a 1998 Audi A4?
Suspension, recorded in 13.0% of tests, followed by lighting & signalling (10.7%).
Does the 1998 A4 get worse with mileage?
Its MOT fail rate rises from 10.7% in the 30-60k band to 26.2% in the 150k+ band.
Methodology & source. Based on 3,744 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.