1986 BMW 6 Series — MOT failures & pass rate
Across 479 MOT tests, the 1986 BMW 6 Series recorded an 86.0% pass rate. Against coupes & convertibles of a similar age (16.1% fail rate), the 1986 6 Series comes out 2.1pp better. Failures cluster in lighting & signalling, suspension and brakes.
What the MOT record shows
No single area dominates — lighting & signalling (6.3%) and suspension (5.2%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp aim, washers and component mounting prescribed areas — headlamp aim alone was recorded 23 times.
Mileage matters less than usual here: the 1986 6 Series fails 13.2% of the time in the 60-90k band and 17.1% at 150k+, a spread of only 3.9 points.
Brakes is the most common advisory, noted on 17.1% of tests — work that passed today but is likely due soon.
The trend is worsening — 11.3% of tests failed in 2021 against 13.6% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 6.3% | 30 |
| 2 | Suspension | 5.2% | 25 |
| 3 | Brakes | 5.0% | 24 |
| 4 | Visibility | 4.4% | 21 |
| 5 | Emissions & environmental | 3.1% | 15 |
| 6 | Body, structure & corrosion | 2.7% | 13 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp aim | 23 |
| 2 | Washers | 22 |
| 3 | Component mounting prescribed areas | 20 |
| 4 | Service brake performance | 16 |
| 5 | Headlamp | 10 |
| 6 | Pins and bushes | 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 | Brakes | 17.1% | 82 |
| 2 | Suspension | 16.9% | 81 |
| 3 | Body, structure & corrosion | 10.2% | 49 |
| 4 | Tyres | 9.8% | 47 |
| 5 | Emissions & environmental | 9.2% | 44 |
| 6 | Steering | 7.1% | 34 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 60-90k | 121 | 13.2% |
| 90-120k | 145 | 13.8% |
| 120-150k | 96 | 12.5% |
| 150k+ | 76 | 17.1% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 97 | 11.3% |
| 2022 | 90 | 17.8% |
| 2023 | 99 | 15.2% |
| 2024 | 90 | 12.2% |
| 2025 | 103 | 13.6% |
What to check before buying a 1986 6 Series
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 6.3% of tests. Start there.
- Lighting & signalling (6.3% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (5.2% 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.
- Brakes (5.0% 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 1986 BMW 6 Seriess pass their MOT?
86.0% of the 479 1986 BMW 6 Series MOT tests in this dataset passed — a 14.0% fail rate.
What is the most common MOT failure on a 1986 BMW 6 Series?
Lighting & signalling, recorded in 6.3% of tests, followed by suspension (5.2%).
Does the 1986 6 Series get worse with mileage?
Its MOT fail rate rises from 13.2% in the 60-90k band to 17.1% in the 150k+ band.
Methodology & source. Based on 479 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.