Why does my BMW 5 Series make a strange noise when I start it?

I recently purchased a BMW 5 Series and have noticed that every time I start the car, it makes a strange noise. It goes away after a few seconds, but it's worrying me. Is this normal or is there something wrong with my car?

This is completely normal and nothing to be concerned about. The BMW 5 Series has a self-diagnostic system that runs when you start the car, which can cause some noise. As long as the noise goes away after a few seconds, your car is functioning as it should.

I have a friend who also owns a BMW 5 Series and they experienced the same thing. They took it to the dealership and were told that it's just the car's engine adjusting to the temperature. It's a common occurrence and nothing to worry about.

I've had my BMW 5 Series for a few years now and it has always made that noise. I spoke to a mechanic about it and they said it's just the sound of the fuel system priming. It's completely normal and nothing to be concerned about.