All generations and engines together · 1,107 MOT tests in the 2025 data
Not enough recent tests to rate this coupé or convertible. Watch brakes and suspension. Not enough recent MOT data to call this one yet.
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.
The 722.6 five-speed auto (fitted across W208 and W209 CLKs) uses a plastic conductor plate inside the valve body that carries the shift solenoids' wiring. It goes brittle with age and heat, causing harsh or delayed shifts, getting stuck in one gear, or the box dropping into limp mode. It typically shows up from around 80,000-120,000 miles and a replacement plate plus dealer programming runs roughly £400-800.
Early W209 CLKs (roughly 2003-2005) got Mercedes' electronic Sensotronic Brake Control instead of a conventional hydraulic setup. A worn ground connection or pump piston out of tolerance can make the system drop into a basic hydraulic back-up mode, giving a long, hard pedal and a warning light. Mercedes ran a recall and free fix in 2005 and later extended the pump warranty to 10 years unlimited mileage, but replacement pumps on unfixed or re-failed cars can run well over £1,000. The MOT signature for this model is brakes, and the SBC pump and its wiring are the specific part of that story that isn't a simple pad-and-disc job.
On both generations the main fuse box (or Front SAM on later W209 cars) sits in the cowl area under drains that clear rainwater away from the windscreen. When those drains clog with leaves, water floods the box and corrodes the bus bars and relay pins, causing random electrical faults: central locking, wipers, lights or the instrument cluster misbehaving. It can appear at any age once the drains are neglected, and a repair means clearing the drains plus a replacement module, coded to the car, from roughly £300 to over £1,000 depending on generation.
A metallic rattle from the top of the engine on acceleration and overrun, most often reported on the four-cylinder 230 Kompressor and the V6 320 cars. It is caused by the camshaft adjuster's control valve gumming up or its magnet wearing, and owners are split on whether it is worth fixing: some call it harmless and cosmetic, others replace the adjuster (£150-300 a side) to stop it getting worse. Not a fault Mercedes ever acknowledged with a recall.
On the drop-top CLK the roof runs on a hydraulic pump with around ten fluid lines and several rams. Seals harden with age, typically from 10-12 years on, and a leak can leave the roof stuck half open or half closed, sometimes worse in cold weather. A single leaking pipe or ram is a manageable fix at £150-300, but tracking down which of the multiple lines has failed adds labour, and a full re-seal or pump replacement can run past £1,000.
The Eaton supercharger fitted to 230 and 200 Kompressor engines is rated for a long service life but owners report seals weeping oil and units smoking under hard acceleration once neglected past 100,000 miles without an oil change, despite Mercedes originally calling it sealed for life. A service or reseal costs a few hundred pounds; a full unit replacement is more. Smoky acceleration on a test drive on these engines specifically is a warning sign, not something to expect on the naturally aspirated cars.
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.
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. 1,105 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 (Coupés, convertibles & GT), best MOT record first. Compare before you shortlist.