All generations and engines together · 293,182 MOT tests in the 2025 data · typical mileage at age 7: 65k
Middling among saloons and estates, by age and by mileage. Watch brakes and suspension. A fair used buy, provided its MOT history has no repeating brakes advisories.
Split by first-registration year. Cars registered in a changeover year can belong to either generation.
Owner folklore from forums and the motoring press, with how well each report stands up. Most of it never shows up in an MOT, which is why this section exists at all.
On the pre-2008 V6 petrol engines (used in the W203 and early W204 C-Class), the balance shaft gear (M272) or idle gear (M273) is made from a soft metal that wears prematurely, especially under stop-start city driving. Symptoms are a check engine light, misfiring and a rattly top end, usually turning up well within 100,000 miles. Mercedes-Benz USA settled a class action over it in 2015 and extended cover to 10 years/125,000 miles on qualifying cars; full repair otherwise runs well into four figures.
On the four-cylinder petrol W205 (2014-2021), owners and independent specialists report a cold-start rattle from worn camshaft adjusters, and a separate but related fault where the tone ring on the camshaft itself slips, throwing up timing codes and sometimes triggering limp mode. It shows up anywhere from 40,000 miles up and a camshaft replacement is not a small job, typically £800-£1,500. Mercedes has recalled a related but distinct camshaft weld fault on some 2015-2016 models; the tone-ring slip itself has no dedicated TSB, it is a known pattern failure rather than an official one.
The four-cylinder OM651 diesel, fitted across W204 and W205 C220d/C250d models, is known for timing chain guides and tensioners wearing out from around 80,000-120,000 miles, first heard as a cold-start rattle that fades once oil pressure builds up. Ignoring it risks a jumped chain and serious engine damage. Piezo injectors on pre-2012 cars also have a higher-than-average failure rate past 100,000 miles. A chain kit runs roughly £600-£1,000 fitted; injectors add more on top if several need replacing.
Cars fitted with the optional AIRMATIC air suspension can develop leaking air springs, which force the compressor to run constantly until it overheats and wears out. The giveaway is the car sitting noticeably lower on one corner, especially after sitting overnight, or a compressor that runs longer and louder than it used to. A relay fix is cheap, but a full strut-plus-compressor repair typically runs £950-£1,650.
W205-era cars have a repeated owner complaint of the central COMAND screen developing horizontal scrolling lines, freezing, or losing sat-nav and media functions entirely. It is not officially acknowledged as a defect and fixes range from a software reset to a full head unit or screen replacement, £300-£800 depending on what is swapped.
A long-running owner complaint on both W204 and W205 cars: a pulsing through the pedal or steering under braking, often blamed on "warped" discs but more often down to friction-material transfer, corroded hubs, or an uneven-wearing pad, needing a disc and pad set well before the mileage a normal car would need one. This lines up with the measured MOT data, where brakes are the standout fail category for this model versus similar saloons and estates; the forums mostly argue about the cause rather than whether it happens.
Ranked from this model’s own MOT record, then from what owners report.
Saveable checklistThe physical checks its own defect data says are worth your time, most telling first.
These judge the seller’s upkeep rather than the model, and they are where the haggling money is.
The physical checks its own defect data says are worth your time, most telling first.
These judge the seller’s upkeep rather than the model, and they are where the haggling money is.
The physical checks its own defect data says are worth your time, most telling first.
These judge the seller’s upkeep rather than the model, and they are where the haggling money is.
Drawn from the reports above rather than the MOT data. These are the model-specific ones.
Computed from DVSA MOT results, all of Great Britain, 2025. Nothing here is opinion.
Share of tests where each item was recorded. The dark tick is the class average across all tracked models; bars are scaled within each group.
The rows that judge the model rather than its keeper. 131,410 tests in this band.
Tyres, pads and stone chips say more about how the car was driven and maintained than about how it was built.
Same segment (Saloons & estates), best MOT record first. Compare before you shortlist.
Head to head with the other popular cars in its class on reliability and common faults.