Noise from cold.

[Sgr74]

My wee motor (2.5 roadie) has a slight dull knocking noise just behind my head In the boot when I first move off. Once I’ve gone a few miles, everything is fine And all is quiet. I’m assuming it’s my bushes warming up and doing their job. Does anyone else have this?

 

[Ewazix]

It could be the start of the well known click/clunk from the prop shaft rear spines, rectified by lubricating with a BMW specified grease. I've not had this but there have been loads of posts about it over the years, apparently it requires a fair bit of labour to access it.

It's also worth checking for worn bushes on the rear end and engine / box as they may be allowing excess drivetrain movement as well.

Here's one of the many threads https://z4-forum.com/forum/viewtopic.php?f=3&t=30050