Overview

Mercedes-Benz went through a rough patch in the late 1990s to early 2000s, and the W204-generation of C-Class introduced in 2007 was an effort to correct this dip in its reputation. Sold until 2014, with a facelift bringing further improvements in 2010, the consensus is that this Mercedes C-Class did manage to do exactly that. It has an excellent reputation for reliability, and with prices now starting at under £3,000 represents great value as a used car.

Key rivals include the design-orientated Audi A4, and the driver-focused BMW 3 Series – but neither offers the cache of that three-pointed star.

Mercedes C-Class W204 known faults and common problems

While we can understand the appeal of a budget Benz, you’d probably be safer not going for the very cheapest examples with mega-mileage – even though if you find one with fully documented service history there’s not that much reason to fret. But for all that it can last a very long time, there are still a few critical issues you must look out for when buying a second-hand C-Class W204.

We’ve listed the main ones below. Remember to always examine the MOT certificates. It’s also worth getting a vehicle history check for added peace of mind.

Buying guide

Common issues, what to look for if you’re looking at getting one.

1) Timing chain failures

The engines fitted to the W204 are generally reliable, so don’t be too put off by the first three entries here. That said, you really don’t want a timing chain failure, so do pay attention.

Six-cylinder petrols were prone to premature timing chain ‘stretching’, so don’t think a low-mileage car will be safe. And since timing chain replacement is an expensive job on any of the C-Class’s motors, make sure it’s not due imminently after purchase – or negotiate accordingly.

2) Petrol engine issues

A few things can go wrong with the W204’s petrol engines, including Mass Air Flow sensors (rough running should indicate that), issues with the sensors related to the crankshaft (loss of power and difficulty restarting are the clues there), and failure of the controller for the variable valve timing system.

Also watch out for fuel leaks (often the fuel filter flange) and dripping water pumps. As with the timing chains, you really don’t want the water pump to fail while on duty.

3) Diesel engine issues

The diesel engines had injector issues early on, and while this should have been sorted by this point, the age of the oldest W204s mean you should be mindful of injector replacement coming round again. Certainly, the o-rings that seal them can leak, as can other engine seals – in many cases Mercedes has issued a more wear-resistant part.

Other diesel problems include temperature sensors, and oil getting into the turbo inlet via the positive crankcase ventilation (PCV) valve. On the bigger diesel engines a ticking noise at idle may indicate damage to the crankshaft main bearing shells. Walk away.

4) Power steering leaks

Power steering leaks are most common on pre-facelift cars, but again as time marches on may affect more examples. Unusual noises and a lack of smoothness when turning the wheel are the symptoms.

5) Steering lock and column

Speaking of the steering, the W204 C-Class has been known to suffer with issues relating to the electronic key and the steering column. This is expensive to fix.

Symptoms include ignition lights not coming on, the steering lock not releasing and the electronic key not being recognised.

6) Gearbox issues

Many post-facelift models were fitted with the 7G-Tronic automatic gearbox – a seven-speed unit that represented a decent leap forward over the old five-speed auto at the time. However, they don’t seem to last that well. If gearchanges are harsh, jerky or otherwise unpleasant, the root cause – often a valve – can cost thousands to fix.

Meanwhile, the six-speed manual fitted to some diesel models can experience premature dual-mass flywheel failure. On any example with over 60,000 miles, check the paperwork to see if this – and the rest of the clutch pack – has already been replaced.

7) Do the lights all work?

Moisture can get into the Xenon headlights and the control module for the indicators, while the rear lamps are known to suffer earthing issues (this last shouldn’t cost too much to repair).

Worth checking everything illuminates as it should when you’re viewing, rather than discovering an issue while you’re driving it home in the dark.

8) Rust

Rust shouldn’t be a big problem on these, and may indicate poor treatment or accident repair. However, around the boot area in particular is becoming more common to oxidisation over time.

Unfortunately, one area of the car that does suffer from tin worm more than others is the rear subframe. Not a cheap fix – so check the MOT history for any reports of corrosion.

9) Electronics

Not really a surprise as a complex premium vehicle gets older, but the W204 C-Class can suffer with electronic sensor failures affecting everything from the wipers to sunroof, not to mention the electronic stability control system and the brakes.

None of this should be a huge deal, but make sure it’s all accounted for in the asking price.

10) Wear and tear

Interiors don’t seem to last that well, especially where leather is fitted. Disappointingly, the steering wheel trim can also disintegrate – annoying when it’s something you interact with all the time. The facelift solved an early creaking dashboard issue, but by this point we’d expect any high-mileage example to make a few uncouth noises.

Tailgate hinges and folding mirrors can make irritating noises as well. The former may just require lubrication, the latter a cheap replacement internal part.

You should, however, pay attention to any knocking noises or other unusual sounds from the suspension. This could indicate worn components, with the bushes in particular being prone to wear. Mercedes even introduced harder items for some areas of the W204 during its lifetime.

What models and trims can you buy?

Standard model lines for the W204 C-Class saloon include SE, Executive SE, Sport, Elegance and three flavours of AMG: AMG Sport, AMG Sport Edition and AMG Sport Plus. This are not to be confused with the full-fat high-performance AMG C63 model, which is a different beast entirely.

With the arguable exception of the entry-level SE, all come with a reasonable – but not especially generous – amount of standard equipment, which buyers could add to via an extensive options list.

A wide selection of four and six cylinder petrol and diesel engines were offered. Diesel models are indicated by CDI badging, while later petrols were labelled CGI, indicating newer direct injection engines (which are more efficient but also more prone to carbonisation, and best run on high-quality fuel).

We have a separate equivalent C-Class Estate review.

Over the next few pages, we’ll examine each aspect of this Mercedes-Benz C-Class, taking into account its practicality, comfort, fuel economy and performance. If you’re short on time, you can also skip to our verdict page to see if we recommend the C-Class W204 as a good used car.