2003 Mercedes-Benz Clk — MOT failures & pass rate
Across 21,664 MOT tests, the 2003 Mercedes-Benz Clk recorded a 75.0% pass rate. Against coupes & convertibles of a similar age (22.6% fail rate), the 2003 Clk comes out 2.5pp worse. Failures cluster in suspension, lighting & signalling and brakes.
What the MOT record shows
No single area dominates — suspension (14.2%) and lighting & signalling (12.3%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are headlamp aim, coil spring and ball joint — headlamp aim alone was recorded 1,762 times.
A 150k+ example is materially riskier than a 0-30k one: 30.1% versus 13.1%.
Split by fuel, diesel examples fail 4.7pp more often than petrol ones (29.1% vs 24.4%) — worth weighing if you have a choice.
Advisories point at the next bill rather than this one: brakes was flagged on 37.0% of tests without failing them.
The trend is improving — the fail rate fell from 26.0% in 2021 to 22.6% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Suspension | 14.2% | 3,079 |
| 2 | Lighting & signalling | 12.3% | 2,666 |
| 3 | Brakes | 8.2% | 1,771 |
| 4 | Tyres | 5.6% | 1,221 |
| 5 | Visibility | 4.3% | 926 |
| 6 | Emissions & environmental | 3.8% | 814 |
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 | 1,762 |
| 2 | Coil spring | 1,423 |
| 3 | Ball joint | 1,253 |
| 4 | Headlamp | 1,206 |
| 5 | Rigid brake pipes | 917 |
| 6 | Pins and bushes | 791 |
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 | 37.0% | 8,013 |
| 2 | Suspension | 33.1% | 7,170 |
| 3 | Tyres | 25.7% | 5,574 |
| 4 | Lighting & signalling | 17.1% | 3,702 |
| 5 | Emissions & environmental | 11.2% | 2,421 |
| 6 | Other defects | 9.9% | 2,143 |
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 | 419 | 13.1% |
| 30-60k | 1,951 | 16.9% |
| 60-90k | 5,185 | 23.8% |
| 90-120k | 6,808 | 25.1% |
| 120-150k | 4,425 | 27.5% |
| 150k+ | 2,772 | 30.1% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 18,686 | 24.4% |
| Diesel | 2,967 | 29.1% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 5,628 | 26.0% |
| 2022 | 4,982 | 25.4% |
| 2023 | 4,413 | 25.6% |
| 2024 | 3,650 | 24.4% |
| 2025 | 2,991 | 22.6% |
What to check before buying a 2003 Clk
On a 2003 Clk, suspension is what the MOT record says goes wrong most — it appeared in 14.2% of tests. Check these areas before you commit.
- Suspension (14.2% 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.
- Lighting & signalling (12.3% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (8.2% 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 Clks pass their MOT?
75.0% of the 21,664 2003 Mercedes-Benz Clk MOT tests in this dataset passed — a 25.0% fail rate.
What is the most common MOT failure on a 2003 Mercedes-Benz Clk?
Suspension, recorded in 14.2% of tests, followed by lighting & signalling (12.3%).
Does the 2003 Clk get worse with mileage?
Its MOT fail rate rises from 13.1% in the 0-30k band to 30.1% in the 150k+ band.
Methodology & source. Based on 21,664 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.