Have you ever, had the tappets looked at plus adjusted?. Over here certain model cars ,will have more prominent tappet noise than other cars. Can you hear this ticking, specifically originating from the engine?
You mentioned it doesn't do it at idle. I was only guessing about tappets. It is interesting that you don't have this ticking at idle. But you mentioned the tick sound increases, the more you accelerate. Then when you are driving it dissapears. Do you notice an absence of ticking, when the engine has warmed up.?
I was hazarding a guess in context of tappets. My falcons used to have tappet issues. This was only when the engines got old. That tick noise was prominent at idle. The tick increased as i accelerated. Then my tappets ,would decrease in sound volume as the motor warmed up.
I agree with squishy's advice. Can not imagine it doing any harm. That it does not happen at idle confuses me. So it appears i will have to disregard the tappet dilemma. Hope squishy is not offended, but i also are trying to use the process of elimination. Yes, the CV joints should be checked. I had my CV joints replaced in other cars. Obviously changing the oil and doing squishy's experiment is worth a try.
Is coasting, an expression overseas that means cruising? He comments that this noise is absent, when driving down the road. It is not there at idle. Shall eliminate my tappet theory. He is indicating ' ticking' instead of ' tapping'.