One problem related to timing tensioner has been reported for the 2014 BMW 328. The most recently reported issues are listed below.
Took car in for maintenance. Mechanic told me timing chain needed replaced and car could not be driven or it will destroy engine. Mechanic said this is a known issue due to BMW using inferior plactic for tensioner. Mechanic said timing chain meant to last 200k miles. Car has 69k miles. Cost of repair $3200.