Four months and 3 trips to the dealer and I finally have gotten rid of the annoying rattles. This is a post for all those out there hearing weird noises from their engine, I hope this helps. First noise was a "ticking" noise coming from the front of the engine when the A/C is on. Turned out to be the A/C compressor was going bad. Second, a rattling noise that I would hear at low rpms and at idle. The a/c & fan would also seem to trigger it. Turned out to be a bad PCV valve. Both were replaced and no more noises. Finally!