2003 Mercedes-Benz Cl — MOT failures & pass rate
790 MOT tests on the 2003 Mercedes-Benz Cl are in this dataset, and 82.2% of them passed. That is 4.7 percentage points better than coupes & convertibles of a similar age, which fail at 22.6%. Failures cluster in lighting & signalling, suspension and brakes.
What the MOT record shows
No single area dominates — lighting & signalling (7.3%) and suspension (6.7%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp aim, rigid brake pipes and ball joint — headlamp aim alone was recorded 38 times.
A 150k+ example is materially riskier than a 30-60k one: 24.7% versus 8.5%.
Brakes is the most common advisory, noted on 28.3% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 19.1% in 2021 to 13.6% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 7.3% | 58 |
| 2 | Suspension | 6.7% | 53 |
| 3 | Brakes | 4.9% | 39 |
| 4 | Tyres | 4.8% | 38 |
| 5 | Emissions & environmental | 3.5% | 28 |
| 6 | Steering | 1.8% | 14 |
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 | 38 |
| 2 | Rigid brake pipes | 29 |
| 3 | Ball joint | 23 |
| 4 | Catalyst emissions | 16 |
| 5 | Tread depth | 15 |
| 6 | Headlamp | 11 |
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 | 28.3% | 224 |
| 2 | Suspension | 24.9% | 197 |
| 3 | Tyres | 16.8% | 133 |
| 4 | Emissions & environmental | 9.1% | 72 |
| 5 | Lighting & signalling | 7.7% | 61 |
| 6 | Body, structure & corrosion | 7.7% | 61 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 30-60k | 71 | 8.5% |
| 60-90k | 177 | 18.1% |
| 90-120k | 231 | 16.4% |
| 120-150k | 199 | 19.6% |
| 150k+ | 89 | 24.7% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 194 | 19.1% |
| 2022 | 175 | 18.3% |
| 2023 | 154 | 19.5% |
| 2024 | 149 | 17.4% |
| 2025 | 118 | 13.6% |
What to check before buying a 2003 Cl
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 7.3% of tests. Start there.
- Lighting & signalling (7.3% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (6.7% 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 (4.9% 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 2003 Mercedes-Benz Cls pass their MOT?
82.2% of the 790 2003 Mercedes-Benz Cl MOT tests in this dataset passed — a 17.8% fail rate.
What is the most common MOT failure on a 2003 Mercedes-Benz Cl?
Lighting & signalling, recorded in 7.3% of tests, followed by suspension (6.7%).
Does the 2003 Cl get worse with mileage?
Its MOT fail rate rises from 8.5% in the 30-60k band to 24.7% in the 150k+ band.
Methodology & source. Based on 790 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.