BMW 635d — MOT pass rate & failures
The BMW 635d recorded a 81.7% MOT pass rate across 9,446 tests in this dataset (model years 1984–2017), with suspension, tyres and lighting & signalling its most common failure areas. Its 18.3% 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 |
|---|---|---|---|
| 2007 | 1,066 | 81.2% | 18.8% |
| 2008 | 3,179 | 81.5% | 18.5% |
| 2009 | 2,518 | 81.5% | 18.5% |
| 2010 | 2,625 | 82.4% | 17.6% |
| 2011 | 39 | 87.2% | 12.8% |
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Suspension | 8.3% | 780 |
| 2 | Tyres | 6.0% | 569 |
| 3 | Lighting & signalling | 4.7% | 439 |
| 4 | Brakes | 4.0% | 379 |
| 5 | Steering | 2.8% | 268 |
| 6 | Visibility | 2.4% | 227 |
| 7 | Emissions & environmental | 0.9% | 90 |
| 8 | Road wheels | 0.9% | 82 |
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 | 453 |
| 2 | Tread depth | 275 |
| 3 | Track rod end | 274 |
| 4 | Linkage ball joint dust cover | 212 |
| 5 | Rbt (sp) | 187 |
| 6 | Coil spring | 176 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Tyres | 24.8% | 2,346 |
| 2 | Suspension | 21.3% | 2,013 |
| 3 | Brakes | 18.1% | 1,705 |
| 4 | Emissions & environmental | 11.2% | 1,058 |
| 5 | Other defects | 7.3% | 686 |
| 6 | Visibility | 4.5% | 422 |
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 | 51 | 13.7% |
| 30-60k | 385 | 11.4% |
| 60-90k | 1,632 | 15.1% |
| 90-120k | 2,857 | 18.9% |
| 120-150k | 2,424 | 19.4% |
| 150k+ | 2,089 | 19.9% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 2,070 | 18.3% |
| 2022 | 2,039 | 19.1% |
| 2023 | 1,914 | 18.4% |
| 2024 | 1,799 | 18.4% |
| 2025 | 1,624 | 16.9% |
What to check before buying a BMW 635d
Focus on the areas it most often fails on — and remember MOT data covers testable defects only, not engine or gearbox health.
- Suspension (8.3% 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.
- Tyres (6.0% of tests): Usually a quick, known-cost fix, but check tread, age and uneven wear (which can hint at alignment or suspension issues). Typical repair: £50–£120 per tyre.
- Lighting & signalling (4.7% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
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 635d at MOT time?
81.7% of the 9,446 BMW 635d MOT tests in this dataset passed — a 18.3% fail rate, worse than the 15.5% average across all 6 Series versions.
What is the most common MOT failure on a BMW 635d?
Suspension, recorded in 8.3% of tests, followed by tyres (6.0%).
Does the 635d get worse with mileage?
Its MOT fail rate rises from 13.7% in the 0-30k band to 19.9% in the 150k+ band.
Methodology & source. Based on 9,446 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.