Oh, that's my car, and the sound is different as far as I can hear from the videos above.

 

Ah, good to know!

Mine is still rattling on startup, goes away when hot.
I’m may get a second opinion at some point, other than that it’s a documented complaint now so if something let’s go…

 

My 2017 D5 developed the same rattle a couple of months ago. Took it into the dealer and they fixed it under warranty. Invoice states it was a: "defective idler pulley (on top of alternator)". Attached the video pre the fix - it sounded the same as yours. Hope this helps...

 

They did the same thing on mine, came back 6 months later.

 

So the new idler gets rid of the sound, but then it comes back?
So are JLR correct that the sound is “normal” at least as far as their poor quality idler goes?
Or as all examples don’t do it and replacement idlers fall foul of the same problem is something out of alignment on some engines which puts some force on the idler in an unintended direction causing premature wear?

 

That is a good question. I also notice that the noise will come after not having driven the car for a while or during the cold season. When the car is warm and in summer you never hear it... Anyway, I learned to live with it

 

That’s interesting… the dealer did suggest the problem may be due to my not driving the car much at all the last year and is wondering if the noise will go away when I use it every day like I am about to do the next 2 weeks. If yours is quiet when regularly used then maybe there is something to that… although I’m scratching my head as to why that would be…
as for winter, we’ll, it is cooler in winter than summer but I was getting the noise on a regular t shirt and shirts spring day here in Texas, and the car is garaged overnight so it’s not what I would describe as cold, but again, maybe there is something to that too…