Beach it sounds like the noise is coming from the timing belt?? I could be wrong?? It doesn't sound metallic, more serpentine like??Sometimes it can sound a little different at start up, or have additional "noises" but typically nothing to worry about. The same for a 2.2L rental I had and our '08 2.4L, but typically just a whisper hum at idle.
What kind of sound or sounds, specifically, seem odd to you now?