Here it is after warm-up. Note the clatter from the front chain area is hard to hear. Seems much quieter and almost gone. I'll do a test tomorrow from cold start in the morning to see how long it take to quiet down.

BMW X5 2004 4.4 185000km Idle 4 - YouTube

I can hear the clatter when it started but seems to get quieter as it runs. I hear the exhaust leak sound that you mentioned. If it the problem is timing guides it is something to correct ASAP so I would have a BMW specialist look at it VERY soon.

Mine sometimes does that every once in a while, except for me its a combination of the broken engine cover (its loose so it clatters) and some misc plastic pieces. Have you had it inspected yet?

Going in Monday for an assessment. I'll keep you all posted.

good luck!!!

Shop looked at it and said it was fine (he has seen enough of these to know). He gave me some engine cleaner to use right before next oil change. I'll keep an eye on the noises to make sure they stay the same and don't get worse. I'll also drop the oil pan at next oil change to see if any plastic or metal in the bottom of the pan.

Good plan.