1998 Mercedes-Benz Clk — MOT failures & pass rate
The 1998 Mercedes-Benz Clk passed 76.9% of its 1,690 recorded MOT tests. That is 1.4 percentage points worse than coupes & convertibles of a similar age, which fail at 21.7%. Failures cluster in lighting & signalling, brakes and suspension.
What the MOT record shows
Lighting & signalling dominates the failure mix at 15.6% of all tests — 6.3 points clear of brakes, so it is the first thing to check.
At component level the recurring items are headlamp aim, position lamp and component mounting prescribed areas — headlamp aim alone was recorded 141 times.
Mileage is the strongest signal on the record: 12.5% of 0-30k cars fail, rising to 32.6% once past 150k — 2.6× the risk.
Advisories point at the next bill rather than this one: brakes was flagged on 35.8% of tests without failing them.
The trend is improving — the fail rate fell from 23.6% in 2021 to 21.4% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 15.6% | 263 |
| 2 | Brakes | 9.2% | 156 |
| 3 | Suspension | 7.8% | 132 |
| 4 | Tyres | 5.6% | 95 |
| 5 | Emissions & environmental | 4.9% | 83 |
| 6 | Body, structure & corrosion | 4.7% | 80 |
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 | 141 |
| 2 | Position lamp | 87 |
| 3 | Component mounting prescribed areas | 87 |
| 4 | Headlamp | 85 |
| 5 | Catalyst emissions | 85 |
| 6 | Individual direction indicators | 67 |
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 | 35.8% | 605 |
| 2 | Suspension | 31.1% | 525 |
| 3 | Tyres | 26.0% | 439 |
| 4 | Lighting & signalling | 18.0% | 304 |
| 5 | Emissions & environmental | 16.5% | 279 |
| 6 | Other defects | 12.8% | 216 |
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 | 48 | 12.5% |
| 30-60k | 190 | 18.4% |
| 60-90k | 420 | 19.1% |
| 90-120k | 451 | 21.7% |
| 120-150k | 325 | 27.4% |
| 150k+ | 239 | 32.6% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 479 | 23.6% |
| 2022 | 386 | 21.5% |
| 2023 | 331 | 23.6% |
| 2024 | 274 | 25.2% |
| 2025 | 220 | 21.4% |
What to check before buying a 1998 Clk
On a 1998 Clk, lighting & signalling is what the MOT record says goes wrong most — it appeared in 15.6% of tests. Check these areas before you commit.
- Lighting & signalling (15.6% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (9.2% 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.
- Suspension (7.8% 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.
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 1998 Mercedes-Benz Clks pass their MOT?
76.9% of the 1,690 1998 Mercedes-Benz Clk MOT tests in this dataset passed — a 23.1% fail rate.
What is the most common MOT failure on a 1998 Mercedes-Benz Clk?
Lighting & signalling, recorded in 15.6% of tests, followed by brakes (9.2%).
Does the 1998 Clk get worse with mileage?
Its MOT fail rate rises from 12.5% in the 0-30k band to 32.6% in the 150k+ band.
Methodology & source. Based on 1,690 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.