How do I diagnose a misfire in my BMW 3 Series?

I've been experiencing a rough idle and hesitation while accelerating in my BMW 3 Series. How can I pinpoint which cylinder is misfiring and what could be causing it?

A misfire can be caused by several factors such as a faulty spark plug, ignition coil, fuel injector, or engine control module. First, check for any fault codes using a diagnostic scanner. If you have a specific cylinder misfire code, you can use a multimeter to test the spark plug and ignition coil. If those are functioning properly, then it is likely an issue with the fuel injector or engine control module.

One common cause of a misfire in BMW 3 Series is a worn-out ignition coil. It is recommended to replace all ignition coils at once if one is found to be faulty. Also, make sure to use high-quality spark plugs and fuel injectors to prevent future misfires.