E46 M3 Timing Chain Noise
 

My car has about 85K miles and I'm chasing a noise that seems to be in the area of the timing chain. I've completely rebuilt the vanos with all available Beisan parts, replaced the timing chain tensioner, guides, and everything else I can thing of to eliminate this sound. It seems only occur on cold engine start up, after the car sits overnight, for instance, and goes away after the engine runs for about 5 seconds. Is this a normal condition, or have I got a problem?
Thanks!

Might want to take a probe and see if you can determine the source, unless you are definitely sure it's coming from the timing chain. How would you say the noise sounds? Is it a rattle? Can you post a video by chance?