I just read this on another forum! "The Direct Injection system is the cause, The rapid ticking noise on cold start up is the fuel pump (located on the rear of the left cylinder head) building up high fuel pressure. When the engine warm-up is completed, the high pressure fuel pump will continue to tick at a lower rate of approximately one tick per second during idle. The clicking sound is the fuel injectors pulsing on and off under higher fuel pressures. This sound is a normal characteristic of Direct Injection Fuel high pressure fuel system." and then i watched this video but i don't think the video is what we are experiencing, https://www.youtube.com/watch?v=z8P-KHximvs