Buying Report · £14.99
Tools

Common problems by part

Mercedes-Benz CLK exhaust, emissions and leaks problems

DVSA MOT tests 2022–2025 · 16,271 MOT tests · Updated

At 18 years, 5.6 in 100 MOT tests of the Mercedes-Benz CLK failed on exhaust, emissions and leaks, against 6.8 for all class 4 vehicles the same age (all test years; 16,271 MOT tests) [1].

Buying Report £14.99 incl. VAT · one car · no subscription · Not a mechanical inspection.

  • Against all class 4 vehicles the same age: about average for all class 4 vehicles the same age (all test years), 914 MOT tests with a fail
  • By age: seen at 13 ages from 13 to 25 years, 121,510 MOT tests
  • Most common fail: Malfunction indicator lamp: inoperative or indicates a malfunction, 3.3 per 100 MOT tests

Figures are for the model as a whole, not for one car.

What the MOT tests show

What we know

5.6 fails per 100 MOT tests at 18 years, against 6.8 for all class 4 vehicles tested at 18 (all test years). That is about average.

Why it matters

An exhaust, emissions and leaks fail stops the car passing until it is fixed; the most common one is rated major by DVSA.

What to check

Start the car from cold and look for smoke at the exhaust, listen for blowing joints, and look under the engine and gearbox for fresh oil or fluid drips.

Mercedes-Benz CLK exhaust, emissions and leaks fails by age

Mercedes-Benz CLK exhaust, emissions and leaks fails per 100 MOT tests by ageSolid line: the Mercedes-Benz CLK. Dashed line: all cars the same age. The table below lists every value.024613 years: 2.4 per 100 (all cars 4.3), 3,310 MOT tests1314 years: 3.2 per 100 (all cars 5.1), 6,134 MOT tests15 years: 4.0 per 100 (all cars 5.7), 10,186 MOT tests1516 years: 5.1 per 100 (all cars 6.2), 13,481 MOT tests17 years: 5.9 per 100 (all cars 6.5), 14,881 MOT tests1718 years: 5.6 per 100 (all cars 6.8), 16,271 MOT tests19 years: 5.8 per 100 (all cars 7.0), 15,419 MOT tests1920 years: 4.9 per 100 (all cars 7.0), 13,220 MOT tests21 years: 4.4 per 100 (all cars 7.1), 10,286 MOT tests2122 years: 4.4 per 100 (all cars 7.0), 7,370 MOT tests23 years: 5.1 per 100 (all cars 6.9), 5,321 MOT tests2324 years: 5.2 per 100 (all cars 7.0), 3,553 MOT tests25 years: 5.2 per 100 (all cars 7.1), 2,078 MOT tests25
Fails per 100 MOT tests by age, all first-use years pooled. Mercedes-Benz CLK All class 4 vehicles the same age Shaded: over 18 years, survivors only.
AgeMOT testsFails per 100All class 4 vehicles the same age
133,3102.44.3
146,1343.25.1
1510,1864.05.7
1613,4815.16.2
1714,8815.96.5
1816,2715.66.8
19*15,4195.87.0
20*13,2204.97.0
21*10,2864.47.1
22*7,3704.47.0
23*5,3215.16.9
24*3,5535.27.0
25*2,0785.27.1

All first-use years of the Mercedes-Benz CLK pooled at each age, against all class 4 vehicles at that age over all 2022–2025 test years. * Only survivors are still tested at this age.

What fails in the exhaust, emissions and leaks at 18 years

Fails

Advisories (not fails)

Diagnose engine warning light cost

Repair figures are estimates, not quotes: how we estimate repair costs.

Buying a Mercedes-Benz CLK? Check that exact car before the viewing.

Buying Report £14.99 incl. VAT · one car · no subscription · Not a mechanical inspection.

  • Model risks for this year and fuel
  • What similar cars did at their next MOT
  • Repairs ahead
  • Viewing checklist

See a sample report

How to check on a test drive

Start the car from cold and look for smoke at the exhaust, listen for blowing joints, and look under the engine and gearbox for fresh oil or fluid drips.

The most common advisory here in MOT records: Engine oil leaks: leak, but not excessive.

Check one Mercedes-Benz CLK, not the average

The figures here describe Mercedes-Benz CLK cars as a group. These free tools answer for one car. Each line says what the tool reads.

Other Mercedes-Benz CLK problems

Exhaust, emissions and leaks on rival models

Questions people ask

Does the Mercedes-Benz CLK have more exhaust, emissions and leaks problems than other cars?

5.6 in 100 MOT tests at 18 years, against 6.8 for all class 4 vehicles the same age: about average by our test (all test years; 16,271 MOT tests).

How common are Mercedes-Benz CLK exhaust, emissions and leaks problems?

5.6 in 100 MOT tests at 18 years failed on exhaust, emissions and leaks, against 6.8 for all class 4 vehicles the same age (all test years; 16,271 MOT tests).

What is the most common Mercedes-Benz CLK exhaust, emissions and leaks fail?

3.3 in 100 MOT tests at 18 years: Malfunction indicator lamp: inoperative or indicates a malfunction (543 MOT tests with it).

Sources

  1. Driver and Vehicle Standards Agency, Anonymised MOT tests and results, 2022 to 2025. DVSA MOT data, Open Government Licence v3.0, 121,510 MOT tests. Accessed 7 Oct 2026.
  2. Office for National Statistics, Consumer price inflation, local price quotes (car repair items). ONS price quotes, series 610236. Accessed 7 Oct 2026.

Parts: against all class 4 vehicles at the same age, all 2022–2025 test years pooled, not adjusted for mileage. Breakdowns and non-MOT faults are not in this data. How we compare