Knocking/pinging Sound On '13gt

The other day when I parked I noticed a knocking sound coming from the engine bay at idle. It doesn't get any louder when i reved the motor or when I'm driving either. The other thing is that the knocking comes and goes at idle. Anyone have a similar issue? or know what it could be? It's pretty annoying considering it only has 1500 miles

yup i use 93. It happens very randomly at idle and only after drving around for a bit. When i start it up in the morning when I head out, it won't make the sound, even drving it for 10-15 mins somewhere it still may not do it, but when it does do it at idle it will do it for 5-10 seconds, and stop ,and then do it again.