How can I tell the difference between injector sounds and engine tick/engine issues?

I have a 2015 BMW 428i, and I know that a lot of German cars especially Audi and BMW have loud injectors that make a click/tick sound when the engine idles. Mine definitely makes that sound and it drives normally, but I want to know if there are any concrete indicators of the sound being more than the injectors? Or anything else it could possibly be/anything to look at?