2001 Mercedes-Benz SLK — MOT failures & pass rate
The 2001 Mercedes-Benz SLK passed 80.2% of its 14,091 recorded MOT tests. That is 2.7 percentage points better than coupes & convertibles of a similar age, which fail at 22.5%. Failures cluster in lighting & signalling, brakes and visibility.
What the MOT record shows
Lighting & signalling dominates the failure mix at 14.2% of all tests — 7.6 points clear of brakes, so it is the first thing to check.
At component level the recurring items are stop lamp, headlamp aim and catalyst emissions — stop lamp alone was recorded 782 times.
Condition tracks the odometer closely. Failures run at 9.2% in the 0-30k band and 27.2% in the 150k+ band, a 18.0-point spread — more than double.
Advisories point at the next bill rather than this one: brakes was flagged on 31.8% of tests without failing them.
The trend is improving — the fail rate fell from 20.5% in 2021 to 18.8% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 14.2% | 2,005 |
| 2 | Brakes | 6.6% | 936 |
| 3 | Visibility | 5.6% | 794 |
| 4 | Suspension | 4.8% | 678 |
| 5 | Tyres | 4.1% | 581 |
| 6 | Emissions & environmental | 3.8% | 537 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Stop lamp | 782 |
| 2 | Headlamp aim | 780 |
| 3 | Catalyst emissions | 539 |
| 4 | Headlamp | 519 |
| 5 | Wipers | 496 |
| 6 | Position lamp | 467 |
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 | 31.8% | 4,482 |
| 2 | Suspension | 25.8% | 3,636 |
| 3 | Tyres | 24.0% | 3,383 |
| 4 | Emissions & environmental | 13.0% | 1,829 |
| 5 | Lighting & signalling | 11.9% | 1,679 |
| 6 | Other defects | 10.5% | 1,482 |
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 | 404 | 9.2% |
| 30-60k | 2,324 | 13.6% |
| 60-90k | 4,637 | 17.8% |
| 90-120k | 4,265 | 23.1% |
| 120-150k | 1,841 | 24.9% |
| 150k+ | 618 | 27.2% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 3,494 | 20.5% |
| 2022 | 3,135 | 19.3% |
| 2023 | 2,851 | 20.3% |
| 2024 | 2,445 | 19.8% |
| 2025 | 2,166 | 18.8% |
What to check before buying a 2001 SLK
On a 2001 SLK, lighting & signalling is what the MOT record says goes wrong most — it appeared in 14.2% of tests. Check these areas before you commit.
- Lighting & signalling (14.2% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (6.6% 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.
- Visibility (5.6% of tests): Wipers, washers, mirrors and screen damage — usually inexpensive, but check for chips in the driver's line of sight. Typical repair: £15–£150.
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 2001 Mercedes-Benz SLKs pass their MOT?
80.2% of the 14,091 2001 Mercedes-Benz SLK MOT tests in this dataset passed — a 19.8% fail rate.
What is the most common MOT failure on a 2001 Mercedes-Benz SLK?
Lighting & signalling, recorded in 14.2% of tests, followed by brakes (6.6%).
Does the 2001 SLK get worse with mileage?
Its MOT fail rate rises from 9.2% in the 0-30k band to 27.2% in the 150k+ band.
Methodology & source. Based on 14,091 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.