2012 XC60 R Design ticking noise whilst idling
 

Newbie just joined, have a 2012xc60, had this car since 2013, it has 55000 on the clock, runs great! A few days ago I noticed after parking whilst the engine was idling, a ticking sound started, when the engine is revved the noise disappears, anyone on here can shed any light on what it may be? It is definately a ticking sound and not grating or a tapping noise, Cheers in anticipation!