The Mercedes-Benz C320 was one of the trims produced from 2001 to 2007 for the compact luxury car during its second production cycle. The C320 has a host of problems from its five-year production run, although some of them involve recalls, in which the manufacturer--German automaker Mercedes-Benz--assumes responsibility.
The most common problem with the Mercedes C320 concerns its 3.2-litre 215-horsepower V6 engine. Affecting all model years apart from the 2006 version--and most severe with the 2001 and 2002 years--the problem lies specifically with its mass air flow sensor, which the engine uses to measure the amount of air it consumes.
The 2003 C320 is much more likely than other model years to have failure of its lower control arm bushings, without which major clunking can occur when manoeuvring the vehicle. The 2005 C320 is the only model year that has significant problems with the 13-pin transmission electrical connector.
The C320 was among the 4,300-plus 2004 Mercedes-Benz C-Class vehicles recalled in 2003 for a burr on a metal component of the cars' safety belt locking mechanism. Mercedes recalled an additional 61,000 vehicles--this time, for the 2005 and 2006 model years--in 2005 for potentially defective airbag deployment, and in 2008, about 400 vehicles were recalled for faulty electrical components on the dashboard that can adversely affect the electrical fuel pump.
With the burr problem, authorised dealers can replace the seat belts on the C320. To correct the airbag problem, dealers will install a new inflator module. For the electrical issue, the Software Calibration Number will need to be recoded to make sure that the fuel gauge readings are correct and thus disconnect to stop further fuel delivery in case of a car crash.
As of August 2010, it costs £219 for parts and £42 for labour to repair the mass air flow sensor, £44 for parts and £170 for labour to replace the lower control arm bushings, and £22 for parts and £42 for labour to repair the transmission electrical connector. As recalls constitute Mercedes' assumed responsibility for certain manufacturing defects, repairs/replacements under this category of problems are performed free at authorised dealerships. Owners with such C320 problems can contact Mercedes directly, or they can choose to contact the National Highway Traffic Safety Administration (NHTSA) at 888-327-4236.