Sure, sorry for being a bit cranky earlier. In as layman terms as possible, there is a retaining-pin that holds the camshaft into the most retarded position when you shut off the car. It is not designed to unsecure the mechanism on a cold-start. On a cold-start your oil has settled in the sump, causing a temporary starvation before the top-end pressure builds up. During that short period the impact/clatter is observed between the housing and VVT internals. That is what you hear. The locking pin secures itself again after approximately 1 second as top end pressure builds up. When the housing is under oil pressure, the noise is masked (it is still there).
Fix is a replacement VVT controller. It consists of a sprocket, gear and a holder.
Your oil will settle in the sump every single time you park it overnight. Heavy oil, light oil, any oil - The top end suffers starvation at any cold-start for the very brief period. That is when the pin that supposed to hold the cam decides to go kaput.
As for the guy throwing personal attacks: Please man, facts matter, opinions do not. As for newbie, I know who I am and what I know.