Hey guys,

I have a '14 F56 that is making an odd noise when I start it. It happens when the car has been sitting for a few hours or more and only lasts 15-20 seconds. A tinny rattle is coming from the engine area. I took it to the dealer and they couldn't replicate it, of course. They did activating the fan, fuel pump and whatnot and no problems were found. The best answer they had for me was that it was the purge pump and that noise is normal. Just after I picked up the car the drivetrain malfunction message came up. I turned off and turn back on and it went away. Anyone have any ideas on what could be the root cause of the sound?

Thanks!