Rattling noise from top end (4.8is) - help appreciated :-)

[Lion Heart]

Good point. Yes, I am thinking maybe not cam chain followers because there is no rattle on cold start.

I have some experience of cam chain follower issues with Audi's, and on those because there is initially very little oil pressure and the cam chains are tensioned by oil pressure, you get a rattle on start up for 2-5 seconds.

But from memory (I'm going to double check again later!) there is no rattle on initial start. It comes in after the revs drop to their standard idle (revs are higher when you first start the engine, and settle down after 1-2 minutes, which is when the rattle becomes most evident).

Hopefully not the cam chains, that would be nice :-)

The car is nearing 120k miles.