Repair costs · Mercedes-Benz C-Class

Mercedes-Benz C-Class engine warning light diagnosis: MOT fails on these items more often than other cars of the same age

At MOT, the Mercedes-Benz C-Class fails on items fixed by engine warning light diagnosis at least 1.5 times as often as cars of the same ages and fuel. From 1,528,968 MOT tests at 23 ages (3 to 25 years), DVSA data 2022 to 2025.

MOT data updated 28 September 2026

Mercedes-Benz C-Class, at least, per 100 MOTs (n=1,528,968)2.52

Cars of the same ages and fuel, per 100 MOTs1.61

Times as often≥ 1.5

Ages compared23

What this shows

These are MOT fail items that engine warning light diagnosis fixes, as testers found them on the day of the test. Repairs done between MOTs never show up in MOT data, and mileage is not taken into account, so this is not how often owners pay for the repair.

By age

Fail items fixed by engine warning light diagnosis, per 100 MOT tests, against cars of the same age and the same fuel mix. The model figure is a floor: DVSA data lists each model’s 25 most recorded items per age, and an item outside that list is counted as zero. The comparison figure is a ceiling: an item too rare to be listed for a fuel is counted at its highest possible value.

Mercedes-Benz C-Class: ages with at least 1,000 tests.
Age	Mercedes-Benz C-Class per 100	Same age and fuel per 100	Tests (n)
3 years	0.18	0.49	49,103
4 years	0.56	0.71	72,956
5 years	1.17	0.92	105,976
6 years	1.80	1.10	133,032
7 years	2.57	1.27	143,293
8 years	2.71	1.38	140,055
9 years	2.88	1.49	124,542
10 years	2.99	1.60	115,498
11 years	3.01	1.67	101,794
12 years	3.28	1.79	90,093
13 years	3.17	2.00	78,677
14 years	2.82	2.22	66,178
15 years	2.55	2.32	59,517
16 years	1.99	2.41	56,401
17 years	2.69	2.54	51,777
18 years	3.83	2.72	43,299
19 years	4.34	2.80	33,764
20 years	4.38	2.71	24,530
21 years	4.51	2.58	15,883
22 years	4.00	2.07	9,238
23 years	2.37	1.51	5,618
24 years	0.96	0.97	4,160
25 years	0	0.44	3,584

How we decide: a page exists only when the main generation’s rate, weighted to its own mix of ages and fuels, is at least 1.5 times the rate of cars of the same ages and fuel, from at least 50,000 tests at 3 or more ages, with at least 100 expected items.

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.

What garages charge

Prices are national. They are not specific to the Mercedes-Benz C-Class.

No public source records the price of this whole job, and the time it takes varies from car to car, so we do not publish a single figure. Garages charge by the hour, so ask for a quote that lists labour time and parts. The rates below are what UK garages charge per hour.

The warning light or emissions reading is only the symptom. What the repair costs depends on what the diagnosis finds, so treat any figure as the starting point, not the full fix.

Local garage labour, per hour (65 shops)£78

Local garage, middle half£70 to £96

Main dealer labour, per hour (62 shops)£156

Main dealer, middle half£144 to £174

Median hourly rate charged for car repairs, from 1,058 local garage and 953 main dealer price quotes collected by the ONS, September 2025 to August 2026. The same shops are priced each month, so the number of shops is the real sample.

Engine warning light diagnosis: garage rates and all models

MOT defects this repair fixes

Malfunction indicator lamp inoperative or indicates a malfunction1.46 per 100, all cars

More on the Mercedes-Benz C-Class

Mercedes-Benz C-Class MOT fail rate by age Mercedes-Benz C-Class exhaust and emissions problems Mercedes-Benz C-Class common problems Mercedes-Benz C-Class recalls Mercedes-Benz C-Class ULEZ and clean air zones

Mercedes-Benz C-Class brake pipe replacementat least 1.9 times as often
Mercedes-Benz C-Class suspension ball joint replacementat least 2.2 times as often

Other models that fail on these items more often

Model	Times as often	Tests (n)
Jeep Renegade	at least 2.9	110,103
MG ZSfirst used 2017 or later	at least 2.4	143,170
Nissan Navara	at least 2.4	286,820
Vauxhall Zafira	at least 2.2	861,172
Fiat 500X	at least 2.1	139,151
London Taxis International TX4	at least 2.0	53,539
Volkswagen Beetle	at least 2.0	180,577
Renault Trafic	at least 1.9	428,817
Vauxhall Adam	at least 1.9	237,726
Alfa Romeo Giulietta	at least 1.9	104,085

Looking at a Mercedes-Benz C-Class?

These figures describe all cars, not any one car. Found one you might buy? See what the VetTheCar Buying Report would tell you.

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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, and the MOT inspection manual published on GOV.UK. Prices: ONS consumer price inflation price quotes, September 2025 to August 2026, UK.

MOT data updated 28 September 2026. Prices updated 22 September 2026.

Not affiliated with or endorsed by DVSA or the Office for National Statistics. How we calculate these figures · Data sources