Porsche 924 MOT pass rate & common failures
3,717 MOT tests on the Porsche 924 (1980–2019) give it a 78.3% pass rate. Against all cars of a similar age (19.9% fail rate), the 924 comes out 1.8pp worse. Its most common failure areas are lighting & signalling, visibility and brakes.
What the MOT record shows
Lighting & signalling dominates the failure mix at 13.4% of all tests — 3.7 points clear of visibility, so it is the first thing to check.
At component level the recurring items are washers, service brake performance and headlamp aim — washers alone was recorded 315 times.
Mileage matters less than usual here: the 924 fails 22.0% of the time in the 0-30k band and 19.6% at 90-120k, a spread of only 2.3 points.
Advisories point at the next bill rather than this one: brakes was flagged on 26.0% of tests without failing them.
The trend is improving — the fail rate fell from 23.9% in 2021 to 19.1% in 2025, as the worst-kept examples leave the fleet.
How it compares
By model year
Every 924 model year with a usable sample. Years with their own detailed report are linked.
| Year | Tests | Pass rate | Fail rate | Most common failure |
|---|---|---|---|---|
| 1980 | 113 | 80.5% | 19.5% | Lighting & signalling |
| 1981 | 227 | 83.3% | 16.7% | Lighting & signalling |
| 1982 | 229 | 72.5% | 27.5% | Lighting & signalling |
| 1983 | 332 | 75.3% | 24.7% | Lighting & signalling |
| 1984 | 326 | 76.7% | 23.3% | Visibility |
| 1985 | 401 | 78.3% | 21.7% | Lighting & signalling |
| 1986 | 1,060 | 79.7% | 20.3% | Lighting & signalling |
| 1987 | 510 | 77.3% | 22.8% | Lighting & signalling |
| 1988 | 471 | 79.6% | 20.4% | Lighting & signalling |
Most common failures (all years)
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 13.4% | 499 |
| 2 | Visibility | 9.7% | 361 |
| 3 | Brakes | 9.3% | 346 |
| 4 | Emissions & environmental | 5.4% | 201 |
| 5 | Body, structure & corrosion | 4.8% | 177 |
| 6 | Suspension | 4.6% | 170 |
| 7 | Steering | 2.4% | 90 |
| 8 | Tyres | 1.1% | 42 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Washers | 315 |
| 2 | Service brake performance | 232 |
| 3 | Headlamp aim | 220 |
| 4 | Non catalyst emissions | 153 |
| 5 | Headlamp | 119 |
| 6 | Position lamp | 108 |
| 7 | Wipers | 107 |
| 8 | Component mounting prescribed areas | 104 |
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 | 26.0% | 966 |
| 2 | Suspension | 20.1% | 746 |
| 3 | Emissions & environmental | 13.2% | 491 |
| 4 | Other defects | 11.4% | 425 |
| 5 | Body, structure & corrosion | 9.8% | 363 |
| 6 | Tyres | 8.9% | 330 |
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 | 1,124 | 22.0% |
| 30-60k | 1,053 | 22.0% |
| 60-90k | 1,095 | 21.8% |
| 90-120k | 433 | 19.6% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 952 | 23.9% |
| 2022 | 840 | 20.6% |
| 2023 | 749 | 22.7% |
| 2024 | 625 | 21.0% |
| 2025 | 551 | 19.1% |
What to check before buying a Porsche 924
- Lighting & signalling (13.4% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Visibility (9.7% 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.
- Brakes (9.3% 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
What is the MOT pass rate for the Porsche 924?
78.3% of the 3,717 Porsche 924 MOT tests in this dataset passed, a 21.7% fail rate, across model years 1980–2019.
What does the Porsche 924 most often fail its MOT on?
Lighting & signalling, recorded in 13.4% of tests, then visibility (9.7%).
How much does mileage affect 924 MOT results?
Fail rates run at 22.0% for cars in the 0-30k band and 19.6% for 90-120k, a 2.3-point difference.
Methodology & source. Based on 3,717 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.