Some common problems with the Mazda6 include stalling at low speeds, the engine overheating and battery cable corrosion. The 2004 Mazda6 received the most complaints on CarComplaints.com; of these complaints one of the most common complaints cited engine failure.
According to RepairPal.com, an overheating Mazda6 engine may be caused by a faulty cooling fan control module. This problem is usually fixed by replacing the control module. If the engine is emitting a load ticking noise, the valve lash adjusters may need to be replaced.
As of November 2015, there have been a total of 18 recalls for the Mazda Mazda6. Some of these were due to faulty airbag systems, emission restriction causing fuel leaks and tire pressure issues.