What is this noise? BMW 1 Series

[problemsallthetime]

This morning I started my car and started making this noise but only louder once I started driving the car immediately went back to normal and drove perfectly.

Does anyone know what this noise is?

https://youtu.be/JYAumf1cbLo


Thank you.

[LunarOne]

Sounds like hydraulic tappets. Once oil pressure builds and the tappets fill with oil, the noise should go away. When an engine is rebuilt and the tappets have no oil in them, it can take a few minutes of driving for the noise to go away. Under normal circumstances, the noise should go away within a few seconds of starting the engine. Completely normal in my opinion.

Oh, and welcome to Pistonheads!