Common problems

Mercedes-Benz CLK common problems

What MOT testers find on the Mercedes-Benz CLK: the parts that fail or get advisories most often at each age, against all cars of the same age. From 121,510 DVSA MOT tests taken 2022 to 2025.

MOT data updated 28 September 2026

At 18 years, the most tested age

Suspension fails per 100 MOTs (n=16,271)20.4

All cars at 18 years (n=3,261,622)17.2

Brakes advisories and minor defects per 100 MOTs (n=16,271)34.6

All cars, same age (n=3,261,622)32.3

What stands out

Suspension fails show up on 20.4 of every 100 MOTs of a Mercedes-Benz CLK at 18 years old (n=16,271), against 17.2 for all cars of that age (n=3,261,622).
Lights and electrics fails are less common: 14.4 per 100 MOTs against 21.4 for all cars at the same age.
The fail item testers record most often at 18 years: suspension ball joint worn, on 7.7 per 100 MOTs (all cars 2.4).
The most common advisory or minor defect: rigid brake pipes: corroded, covered in grease or other material, on 17.9 per 100 MOTs.

Problems by part at 18 years

How many of every 100 MOTs found a fail, or an advisory or minor defect, in each area. A test with faults in two areas counts in both.

Mercedes-Benz CLK at 18 years (n=16,271) against all cars at 18 years (n=3,261,622). Per 100 MOTs.
Area	Fails	All cars	Advisories	All cars
Suspension	20.4	17.2	34.4	35.3
Lights and electrics	14.4	21.4	15.4	17.8
Brakes	10.3	12.9	34.6	32.3
Tyres	7.6	7.0	27.0	27.6
Exhaust, emissions and leaks	5.6	6.8	8.5	14.1
Windscreen, wipers and mirrors	5.5	7.3	5.8	6.2
Steering	3.3	3.9	3.2	5.6
Seat belts and airbags	2.7	2.7	1.0	1.3
Body and structure	2.4	8.7	8.6	14.7
Road wheels	1.3	0.5	1.2	1.3
Number plates and VIN	0.5	0.6	3.6	5.5

What testers fail most on the CLK at 18 years

Fail items on the Mercedes-Benz CLK at 18 years (n=16,271), per 100 MOTs, with all cars at the same age (n=3,261,622).
Item	Area	Per 100 MOTs	All cars	Typical repair (estimate)
Suspension ball joint worn	Suspension	7.7	2.4	£75 to £237 per side (rough guide)
Coil spring broken	Suspension	7.0	3.1	£64 to £236 per spring (rough guide)
Headlamp aim: projected beam image is obviously incorrect	Lights and electrics	4.1	4.0	£16 to £39 per car (rough guide)
Malfunction indicator lamp: inoperative or indicates a malfunction	Exhaust, emissions and leaks	3.3	2.5	diagnosis from £39 (rough guide)
Tyre tread below 1.6 mm	Tyres	3.0	2.9	£88 to £145 per tyre
Linkage ball joint dust cover: ball joint dust cover no longer prevents the ingress of dirt	Suspension	2.7	1.8	£33 to £102 per link (rough guide)
Suspension arm bush worn	Suspension	2.7	2.2	£92 to £237 per arm (rough guide)
Handbrake too weak	Brakes	2.6	2.8
Side/position light not working	Lights and electrics	2.5	5.6	£10 to £47 per lamp
Airbag (SRS) warning light on	Seat belts and airbags	2.4	1.3	diagnosis from £39 (rough guide)

Early warnings: advisories and minor defects at 18 years

Advisories and minor defects are recorded, but the car still passes. Across all cars, a part with an advisory or minor defect failed at the next MOT 5.5 times in 100 (n=88,666,940 pairs of consecutive MOTs), against 0.3 times in 100 when the same part had none (n=12,936,860,350).

Advisories and minor defects on the Mercedes-Benz CLK at 18 years (n=16,271), per 100 MOTs, with all cars at the same age (n=3,261,622).
Item	Area	Per 100 MOTs	All cars	If it needs replacing (estimate)
Rigid brake pipes: corroded, covered in grease or other material	Brakes	17.9	12.3	£137 to £392 per car (rough guide)
Tread depth: worn close to legal limit/worn on edge	Tyres	17.5	17.4	£88 to £145 per tyre
Brake discs: worn, pitted or scored, but not seriously weakened	Brakes	8.5	11.1	£148 to £376 per axle (rough guide)
Suspension arm pins and bushes: pin or bush worn but not resulting in excessive movement	Suspension	7.4	8.5	£92 to £237 per arm (rough guide)
Brake pads: wearing thin	Brakes	7.2	6.4	£72 to £174 per axle (rough guide)
Suspension arm ball joint: ball joint has slight play	Suspension	7.1	2.6	£75 to £237 per side (rough guide)
Tyre condition: slightly damaged/cracking or perishing	Tyres	7.1	9.8	£88 to £145 per tyre
Engine oil leaks: leak, but not excessive	Exhaust, emissions and leaks	7.0	12.6
Wheel bearings: has slight play	Suspension	5.8	1.3	£103 to £276 per wheel (rough guide)
Flexible brake hoses: slightly deteriorated	Brakes	5.6	1.9

Repair estimates are a guide for an independent garage: labour at the national median local garage rate (median £78 an hour from 65 garages, ONS price quotes) times estimated labour hours, plus a parts band. Labour hours and most parts bands are estimates, not quotes, and prices vary by model, engine and region. A warning light fault shows the cost of the diagnosis only.

How problems change with age

Fails per 100 MOTs in the three most common areas at 18 years. Ages with fewer than 1,000 tests are not shown.
Age	Tests (n)	Suspension	Lights and electrics	Brakes
13 years	3,310	21.6	10.0	11.2
14 years	6,134	22.6	10.6	10.5
15 years	10,186	21.5	10.8	10.7
16 years	13,481	21.6	11.7	10.8
17 years	14,881	21.3	14.3	10.9
18 years	16,271	20.4	14.4	10.3
19 years	15,419	19.4	15.3	10.2
20 years	13,220	18.4	15.7	10.3
21 years	10,286	15.0	15.6	9.7
22 years	7,370	11.7	15.1	8.4
23 years	5,321	9.3	16.4	9.5
24 years	3,553	7.6	15.6	8.3
25 years	2,078	7.2	16.5	9.3

Mileage

At 18 years, Mercedes-Benz CLK cars showing 30,000 to 60,000 miles failed 26.1% of MOTs (n=1,606); the band that failed most, 120,000 to 150,000 miles, failed 44.4% (n=3,311). For pass and fail rates by age, see Mercedes-Benz CLK MOT fail rates.

What to check on a viewing

On the Mercedes-Benz CLK, testers most often record suspension ball joint worn; coil spring broken; headlamp aim: projected beam image is obviously incorrect. Look at these first, then the areas below.

Suspension

Listen for knocks or clonks over speed bumps and rough roads on the test drive.
Push down hard on each corner: the car should settle at once rather than keep bouncing.
Look behind the wheels for broken or heavily rusted coil springs and split rubber bushes.
Check that the car sits level and that no tyre is worn on one edge only.

Lights and electrics

With someone outside, try every light: dipped and main beam, indicators, brake lights, fog lights and number plate lamps.
Check that the warning lights come on with the ignition and go out once the engine runs.
Look for misted, cracked or yellowed headlamp lenses.

Brakes

On the test drive the car should stop in a straight line without pulling, juddering or grinding.
Look at the discs through the wheels for a deep lip, heavy rust or scoring.
Check that the handbrake or electronic parking brake holds the car on a slope.
Ask when the pads, discs and brake fluid were last changed, and for the receipts.

Ask for the car's MOT history and service record: advisories that repeat from one year to the next show what has been left. GOV.UK MOT history.

Questions

What are the most common problems on the Mercedes-Benz CLK?

At 18 years, the age with the most MOT tests (16,271), the fail items testers record most often on the Mercedes-Benz CLK are suspension ball joint worn (7.7 per 100 MOTs), coil spring broken (7.0 per 100 MOTs), headlamp aim: projected beam image is obviously incorrect (4.1 per 100 MOTs). The most common advisories or minor defects are rigid brake pipes: corroded, covered in grease or other material (17.9) and tread depth: worn close to legal limit/worn on edge (17.5).

Which parts of the Mercedes-Benz CLK fail more often than on other cars?

At 18 years: suspension (20.4 per 100 MOTs against 17.2 for all cars). Compared with 3,261,622 MOTs of all cars the same age.

Mercedes-Benz CLK problems by area

Other Mercedes-Benz models

All Mercedes-Benz models · Common problems by make

Read this with care. A fail rate is not a measure of build quality. How far cars are driven, how they are used and how well owners maintain them all change it, and wear items such as tyres and brake pads are common fails. Compare a model only with cars of the same age. Methodology and limits.

The all cars figures cover all class 4 vehicles (cars and light vans) tested at the same age.

Looking at a Mercedes-Benz CLK?

These figures describe the model, not the car in front of you. Found one you might buy? See what the VetTheCar Buying Report covers, or use the tools that work without a registration.

See a sample report Car tools · MOT fail rates by model · Compare models by MOT record

Repair estimates: ONS consumer price quotes for local garage labour (09/2025 to 08/2026), the MOT inspection manual for defect wording, and estimated labour hours and parts bands. Not affiliated with or endorsed by ONS.

Source

Contains public sector information licensed under the Open Government Licence v3.0. Source: DVSA anonymised MOT test data, class 4 normal MOT tests, 2022 to 2025. MOT data updated 28 September 2026.

Not affiliated with or endorsed by DVSA. How we calculate these figures · Data sources