BMW 635i — MOT pass rate & failures
The BMW 635i recorded a 83.2% MOT pass rate across 2,454 tests in this dataset (model years 1980–2021), with lighting & signalling, suspension and brakes its most common failure areas. Its 16.8% fail rate is higher than the 15.5% average across all BMW 6 Series versions.
How it compares
By model year
| Year | Tests | Pass rate | Fail rate |
|---|---|---|---|
| 1982 | 65 | 84.6% | 15.4% |
| 1983 | 97 | 78.3% | 21.6% |
| 1984 | 126 | 77.8% | 22.2% |
| 1985 | 231 | 79.2% | 20.8% |
| 1986 | 304 | 85.2% | 14.8% |
| 1987 | 223 | 79.4% | 20.6% |
| 1988 | 439 | 83.8% | 16.2% |
| 1989 | 625 | 85.6% | 14.4% |
| 1990 | 129 | 84.5% | 15.5% |
| 2008 | 44 | 79.5% | 20.4% |
| 2010 | 32 | 84.4% | 15.6% |
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 8.3% | 205 |
| 2 | Suspension | 6.4% | 158 |
| 3 | Brakes | 6.4% | 156 |
| 4 | Visibility | 5.8% | 143 |
| 5 | Body, structure & corrosion | 4.3% | 105 |
| 6 | Emissions & environmental | 2.7% | 67 |
| 7 | Tyres | 2.1% | 52 |
| 8 | Steering | 1.6% | 38 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Washers | 124 |
| 2 | Service brake performance | 120 |
| 3 | Headlamp aim | 113 |
| 4 | Component mounting prescribed areas | 86 |
| 5 | Headlamp | 77 |
| 6 | Pins and bushes | 60 |
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 | 18.5% | 453 |
| 2 | Brakes | 16.3% | 399 |
| 3 | Tyres | 11.0% | 270 |
| 4 | Emissions & environmental | 10.9% | 268 |
| 5 | Body, structure & corrosion | 10.0% | 246 |
| 6 | Steering | 6.1% | 149 |
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 | 85 | 15.3% |
| 30-60k | 208 | 16.8% |
| 60-90k | 469 | 13.4% |
| 90-120k | 642 | 18.7% |
| 120-150k | 540 | 16.9% |
| 150k+ | 499 | 17.2% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 554 | 18.2% |
| 2022 | 513 | 17.0% |
| 2023 | 502 | 17.9% |
| 2024 | 438 | 15.1% |
| 2025 | 447 | 15.2% |
What to check before buying a BMW 635i
Focus on the areas it most often fails on — and remember MOT data covers testable defects only, not engine or gearbox health.
- Lighting & signalling (8.3% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (6.4% 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 (6.4% 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 reliable is the BMW 635i at MOT time?
83.2% of the 2,454 BMW 635i MOT tests in this dataset passed — a 16.8% fail rate, worse than the 15.5% average across all 6 Series versions.
What is the most common MOT failure on a BMW 635i?
Lighting & signalling, recorded in 8.3% of tests, followed by suspension (6.4%).
Does the 635i get worse with mileage?
Its MOT fail rate rises from 15.3% in the 0-30k band to 17.2% in the 150k+ band.
Methodology & source. Based on 2,454 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-06. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.