BMW M340d — MOT pass rate & failures
The BMW M340d passed 90.0% of its 5,135 MOT tests, covering model years 2020–2023. That is 7.4 percentage points better than the 17.4% fail rate across all BMW 3 Series versions, so the M340d is a stronger pick within the range. Failures concentrate in tyres, lighting & signalling and emissions & environmental.
What the MOT record shows
At component level the recurring items are tread depth, headlamp aim and registration plates — tread depth alone was recorded 79 times.
Mileage matters less than usual here: the M340d fails 8.7% of the time in the 0-30k band and 9.4% at 90-120k, a spread of only 0.6 points.
Advisories point at the next bill rather than this one: tyres was flagged on 12.3% of tests without failing them.
How it compares
By model year
| Year | Tests | Pass rate | Fail rate |
|---|---|---|---|
| 2020 | 875 | 89.8% | 10.2% |
| 2021 | 3,222 | 90.1% | 9.9% |
| 2022 | 990 | 89.4% | 10.6% |
| 2023 | 48 | 91.7% | 8.3% |
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Tyres | 7.2% | 370 |
| 2 | Lighting & signalling | 1.3% | 64 |
| 3 | Emissions & environmental | 1.0% | 51 |
| 4 | Visibility | 0.9% | 44 |
| 5 | Other defects | 0.6% | 29 |
| 6 | Suspension | 0.5% | 28 |
| 7 | Brakes | 0.3% | 17 |
| 8 | Steering | 0.2% | 12 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Tread depth | 79 |
| 2 | Headlamp aim | 62 |
| 3 | Registration plates | 51 |
| 4 | Malfunction indicator lamp | 43 |
| 5 | Washers | 26 |
| 6 | Wipers | 23 |
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 | 12.3% | 633 |
| 2 | Other defects | 3.5% | 178 |
| 3 | Emissions & environmental | 2.8% | 146 |
| 4 | Visibility | 2.3% | 119 |
| 5 | Brakes | 2.2% | 115 |
| 6 | Suspension | 1.1% | 55 |
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 | 1,660 | 8.7% |
| 30-60k | 3,019 | 10.5% |
| 60-90k | 419 | 11.9% |
| 90-120k | 32 | 9.4% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2023 | 402 | 10.9% |
| 2024 | 1,969 | 10.2% |
| 2025 | 2,761 | 9.8% |
What to check before buying a BMW M340d
Focus on the areas it most often fails on — and remember MOT data covers testable defects only, not engine or gearbox health.
- Tyres (7.2% 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 (1.3% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Emissions & environmental (1.0% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
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 M340d at MOT time?
90.0% of the 5,135 BMW M340d MOT tests in this dataset passed — a 10.1% fail rate, better than the 17.4% average across all 3 Series versions.
What is the most common MOT failure on a BMW M340d?
Tyres, recorded in 7.2% of tests, followed by lighting & signalling (1.3%).
Does the M340d get worse with mileage?
Its MOT fail rate rises from 8.7% in the 0-30k band to 9.4% in the 90-120k band.
Methodology & source. Based on 5,135 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.