1984 Porsche 924 — MOT failures & pass rate
Across 326 MOT tests, the 1984 Porsche 924 recorded a 76.7% pass rate. All cars of a similar age fail 19.7% of the time, so this is 3.6pp worse than the group it competes with. Failures cluster in visibility, lighting & signalling and brakes.
What the MOT record shows
No single area dominates — visibility (13.2%) and lighting & signalling (12.6%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are washers, service brake performance and headlamp aim — washers alone was recorded 40 times.
A 90-120k example is materially riskier than a 0-30k one: 28.4% versus 20.4%.
Advisories point at the next bill rather than this one: suspension was flagged on 30.7% of tests without failing them.
The trend is improving — the fail rate fell from 28.2% in 2021 to 17.7% in 2024, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Visibility | 13.2% | 43 |
| 2 | Lighting & signalling | 12.6% | 41 |
| 3 | Brakes | 11.0% | 36 |
| 4 | Emissions & environmental | 5.5% | 18 |
| 5 | Suspension | 5.2% | 17 |
| 6 | Body, structure & corrosion | 4.6% | 15 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Washers | 40 |
| 2 | Service brake performance | 27 |
| 3 | Headlamp aim | 24 |
| 4 | Non catalyst emissions | 17 |
| 5 | Headlamp | 13 |
| 6 | Rbt (sp) | 12 |
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 | 30.7% | 100 |
| 2 | Brakes | 26.4% | 86 |
| 3 | Body, structure & corrosion | 16.3% | 53 |
| 4 | Other defects | 14.7% | 48 |
| 5 | Emissions & environmental | 10.7% | 35 |
| 6 | Tyres | 9.2% | 30 |
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 | 98 | 20.4% |
| 30-60k | 85 | 25.9% |
| 60-90k | 76 | 19.7% |
| 90-120k | 67 | 28.4% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 85 | 28.2% |
| 2022 | 85 | 24.7% |
| 2023 | 73 | 21.9% |
| 2024 | 62 | 17.7% |
What to check before buying a 1984 924
On a 1984 924, visibility is what the MOT record says goes wrong most — it appeared in 13.2% of tests. Check these areas before you commit.
- Visibility (13.2% 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.
- Lighting & signalling (12.6% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (11.0% 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 1984 Porsche 924s pass their MOT?
76.7% of the 326 1984 Porsche 924 MOT tests in this dataset passed — a 23.3% fail rate.
What is the most common MOT failure on a 1984 Porsche 924?
Visibility, recorded in 13.2% of tests, followed by lighting & signalling (12.6%).
Does the 1984 924 get worse with mileage?
Its MOT fail rate rises from 20.4% in the 0-30k band to 28.4% in the 90-120k band.
Methodology & source. Based on 326 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.