Known APK problem

Mercedes-Benz C-Klasse S204: leaks

On the Mercedes-Benz C-Klasse S204 the APK inspector finds leaks problems 2.0× as often as on cars of the same age: at 13–15 years 11.2%, against about 5.6% nationally.

Illustration Mercedes-Benz C-Klasse S204

Window: Oct 2025 – Sep 2026 · Updated: 16 Oct 2026

What is it?

Leaks of oil, coolant or other fluids.

Repair indication: mediuma targeted repair at the garage.

How to check it at the viewing

Look under the engine and where the car was parked. Open the bonnet and look for wet, greasy spots.

Ask the seller: Does the car lose oil or coolant?

By age

Share of inspected Mercedes-Benz C-Klasse S204s with this defect, compared with all cars of the same age.

Age	Type	C-Klasse S204	95%-CI	National	Difference	n
11 – 12 years	C	2.7%	1.9 – 3.7%	2.7%	1.0×	1,296
13 – 15 years	C	11.2%	10.2 – 12.2%	5.6%	2.0×	3,530
16+ years	A	0.3%	0.1 – 0.6%	0.2%	2.0×	1,859
16+ years	C	6.0%	5.0 – 7.1%	12.0%	0.5×	1,859

A = structure, safety or costly mechanics; B = fail, usually simple; C = advisory. An age is missing when this defect is not among the most common there.

Comparable cars at 13–15 years

Model	Leaks	Vs. national
Mercedes-Benz C-Klasse S204	11.2%	2.0×
Mercedes-Benz B-Klasse W245	1.2%	0.2×
Hyundai i30 I	0.4%	7.6×
Mazda Mazda3 (BL)	2.6%	0.5×
Hyundai i30 II	1.1%	0.2×
Daihatsu Cuore (L276)	0.9%	0.2×

Looking at a Mercedes-Benz C-Klasse S204? Check that car

Enter the plate and see the APK history, open recalls and how this car compares with other Mercedes-Benz C-Klasse S204s of the same age.

All weak spots of the Mercedes-Benz C-Klasse S204 · Leaks: which models more often · Checklist for this model

Frequently asked questions

Does the Mercedes-Benz C-Klasse S204 often have leaks problems?

Yes, more often than average at the APK. At 13–15 years the inspector found a leaks defect on 11.2% of inspected Mercedes-Benz C-Klasse S204s, against about 5.6% of all cars of the same age (2.0×). Source: RDW Open Data, Oct 2025 – Sep 2026.

How do you check the leaks on a used Mercedes-Benz C-Klasse S204?

Look under the engine and where the car was parked. Open the bonnet and look for wet, greasy spots.

Repair indication: small, medium or large. An indication of the usual repair, not a quote: the real cost depends on the car, the cause and the garage.

Source: RDW Open Data (CC0), analysis CarXray.nl. 6,857,004 inspected passenger cars aged 3 years and older, Oct 2025 – Sep 2026. Each car counts once. How we know