2004 Mercedes-Benz Cl — MOT failures & pass rate
Across 407 MOT tests analysed for the 2004 Mercedes-Benz Cl, the most common recorded failure areas were lighting & signalling, suspension and brakes. Its pass rate of 84.5% was above the average for cars of a similar age (74.2%).
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 6.4% | 26 |
| 2 | Suspension | 5.7% | 23 |
| 3 | Brakes | 5.4% | 22 |
| 4 | Emissions & environmental | 4.7% | 19 |
| 5 | Tyres | 3.7% | 15 |
| 6 | Visibility | 2.7% | 11 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Malfunction indicator lamp | 16 |
| 2 | Service brake performance | 15 |
| 3 | Rigid brake pipes | 13 |
| 4 | Ball joint | 10 |
| 5 | Shock absorbers | 10 |
| 6 | Wipers | 9 |
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 | 27.5% | 112 |
| 2 | Suspension | 22.4% | 91 |
| 3 | Tyres | 19.9% | 81 |
| 4 | Emissions & environmental | 10.3% | 42 |
| 5 | Lighting & signalling | 7.4% | 30 |
| 6 | Body, structure & corrosion | 6.6% | 27 |
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 | 74 | 17.6% |
| 60-90k | 147 | 15.7% |
| 90-120k | 112 | 14.3% |
| 120-150k | 39 | 10.3% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 84 | 16.7% |
| 2022 | 93 | 16.1% |
| 2023 | 86 | 18.6% |
| 2024 | 75 | 14.7% |
| 2025 | 69 | 10.1% |
What to check before buying a 2004 Cl
Before buying a 2004 Mercedes-Benz Cl, focus on the areas it most often fails on. Lighting & signalling accounted for 6.4% of tests for this year.
- Lighting & signalling (6.4% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (5.7% 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 (5.4% 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 many 2004 Mercedes-Benz Cls pass their MOT?
84.5% of the 407 2004 Mercedes-Benz Cl MOT tests in this dataset passed — a 15.5% fail rate.
What is the most common MOT failure on a 2004 Mercedes-Benz Cl?
Lighting & signalling, recorded in 6.4% of tests, followed by suspension (5.7%).
Does the 2004 Cl get worse with mileage?
Its MOT fail rate rises from 17.6% in the 30-60k band to 10.3% in the 120-150k band.
Methodology & source. Based on 407 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-01. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.