We put the PO for the car in April 2006, it was built May 2006, and we picked up in Munich June 9th 2006.
The main trend which we have noticed since the problem started in December is that the noise crops up most when we do in-town driving.
For example, I can't say that I've ever noticed it when I start the car up in the morning and drive on the highway 25-30 minutes to work. Nor when I start it up and go somewhere in town for lunch. But 1 hour after lunch, when I start it up, I DO hear it. It lasts for sporadically thru the drive while I drive back to work. Then I start it up, drive back home, no problem. Go get groceries in town, no problem. Start it up, hear it, drive to another errand, the ticking may last the whole trip or it may peter out. Start it back up, and there it is again. Now at this point, if I sit in the car at idle, it usually goes away after 5 minutes or so. However, there have been times when I am waiting to pick someone up, and after idling for ~15minutes it comes up with a vengeance. While I am just sitting there. Hit the gas, and ticking accelerates. Then it disappears. Or continues ticking.
If I happen to drive to the gym (15 minutes, right in town) in the morning, again, don't hear it. After about 1.5 hrs in the gym, start it back up, & I DO hear it. Drive 10 minutes clattering away. Stop and get coffee. Start back up, Hear it. Let it idle 5 minutes, hit the throttle a few times, and it usually dissipates and I go on my merry way.
My husband works pretty close to home, and when he drives in the morning, he also won't hear it, but he will when he does the lunch thing, it crops up there too.
So to summarize, shutting the engine off after only ~15 minutes of driving usually brings out the beast next time you use the car, if it is started up within that same hour or two..
My conclusion is that our car is trying to tell us to stop running errands and drive 75+ mph.
330xi | 6-speed | Sparkling Graphite | Sport Package | iPod Adapter| BlackLines| F1 Pinnacle 35%