Advice for buyers
What should I look for in a used Mercedes C-Class saloon?
A prestige brand image isn’t always an indicator of superior quality, as the data for the Mercedes C-Class shows in our reliability survey, with nearly a third of cars presenting a problem.
This list of faults reported have been numerous, so you'll need to check everything. Try all the electrical items work while you poke around the interior, try the sat nav and make sure the air-con blows cold air and that there are no weird smells. During your test drive, listen out for any interior rattles; pay attention to the gearbox and that it operates smoothly and that there are no nasty knocks and bangs from the suspension over bumps.
Incorrect engine undertray
The wrong engine undertray was fitted to some C-Class' built between 1 March 2018 and 31 March 2018, but this can easily be rectified by a Mercedes dealer who will check and replace it if necessary.
Front seat frame
The welds on the seat frames of the front AMG performance seats fitted to cars manufactured from 8 June 2017 and 2 June 2018 could fail during a collision. Find out from a Mercedes dealer if your car is affected because they will need to inspect the seats and repair them if found to be faulty.
Emissions software update
A number of C200d models fitted with the Renault-sourced 1.6-litre diesel engine and were made from 1 August 2014 to 31 May 2018 will need to have a software update performed by a Mercedes dealer to improve exhaust emissions, and have a supplementary booklet added alongside the owner's manual.
A software issue could lead to the start/stop function being disabled and cause the engine to stall. This issue can be rectified with an update that can be performed by a Mercedes dealer.
A small number of vehicles built between 6 February 2019 and 12 February 2019 might have incorrectly fitted tie rods on the front suspension. If your car is affected, it will need to be checked over by a dealer, who'll rectify the issue for you.
Cracked lock nut
A lock nut used in the steering gear of some models made from 1 March 2015 and 31 October 2018 could be cracked, and will need to be inspected and replaced by a Mercedes dealer.
Electronic Stability Program (ESP)
A certain number of cars made from 1 June 2017 to 30 November 2018 have a software issue with the electronic stability program (ESP) that will need to be reprogrammed by a Mercedes dealer to ensure it works as intended.
This applies to the high-performance AMG models made between 1 June 2014 and 31 May 2016 where the rear axle mountings could break under extreme circumstances, such as full acceleration on a wet surface or when repeatedly breaking traction of the rear wheels. If your car is affected, it'll need to have some software updates applied by a Mercedes dealer to the ESP and electronic chassis control units to limit performance during such scenarios.
Mounting bolts of the turbocharger oil return line
A small number of cars made from 1 December 2018 and 31 January 2019 that need to have the bolts that hold the turbocharger oil return lines in place replaced, but a Mercedes dealer will be able to inform you if your example is affected.
There have been three recalls to the power steering of the C-Class. First is the motor itself that can fail on models built between 1 August 2014 and 31 December 2016 and will need to be replaced. Then there was a software problem on some cars built from 1 November 2017 and 30 April 2018 that require an update. Finally, there is a sensor issue in the system of examples manufactured between 1 July 2018 and 31 August 2018 that could fail. Speak to your Mercedes dealer who'll be able to say if any of these applies to your car.
Is a used Mercedes C-Class saloon reliable?
In our most recent reliability survey, the Mercedes C-Class finished at the bottom of the executive car class in 19th place out of a class of 19.
Reliability rating 87.3%
What went wrong? Non-engine electrics 11%, exhaust 6%, fuel system 4%, battery 3%, bodywork 3%, infotainment/sat-nav 3%, brakes 2%, steering 2%, engine 1%, gearbox/clutch 1%, interior trim 1%
A third of C-Classes went wrong, according to owners, who reported a wide range of issues. Faults rendered more than a third of cars undriveable, and one in four was off the road for more than a week. Although 81% of cars were fixed for free, a small percentage of owners paid out more than £1500 in repair bills.
Owner’s view “This is the worst car I have ever bought. Faults haven’t been properly fixed and the service from the dealer has been poor”