Originally Posted by HJM

The oil type and its viscosity range plays a role in this ticking noise too.Especially the 0-weight oils show this kind of noises after longing periods of no activity. I wouldn't worry about that noise at all! The valve tappets drain totally out and need to refill with oil again one the motor is running!
One would cause more harm by running (idling) the motor every couple days without load and thorough warming!

HJM