New rattling sound at idle
 

This isn't the standard sounds the engine makes. Not sure how to describe it. It happens randomly, only at idle, and you hear it from the drivers side of the engine bay. I tried to listen to it with the engine bay open, but these engines make so many noises. Car runs fine, no bogging, backfiring, nothing. It is just this strange sound at idle.

Could it be too much oil? I took it to the dealership for a free oil change(it took 3 hours, totally not worth it), and I checked the levels today(granted it was hot oil) and it was over the second line. I am writing it the instant I noticed it. I am going back when the car has cooled, making a video, and checking the level again.

When did the noise start?

It started today, but since I noticed it, it hasn't done it since. I couldn't get a recording because it wasn't making the sound. Might have just been me...

As informative as the forum is I think it can also cause us to look for problems that are not really there.
Once somebody posts about a noise or such we all start looking for it to happen to us so even "normal" things start to stand out and annoy.
Just yesterday I was sitting at a light and noticed that my exhaust tone seemed to go up and down. I immediately thought "OH god idle dip"! Looked at tach and it was steady as a rock on 700. Still could hear what I thought was my exhaust going up and down. Rolled down passenger window to listen and could tell right off that it was actually the truck beside me that was making the noise and it just happened to harmonize perfectly with my exhaust tone.
The point being, if I had not read about all the idle issues I would never have know and been paranoid that it was going to happen to me.

Try taking a video of it if you can

I have an idle rattle like that too sometimes. Only hear it from inside but sounds like its in the engine bay. If I pop the hood and listen I can't hear it.. No death yet.

Does this only seem to happen when the car is cold? I seem to have a similar sort of ratttling sound, but I'm not sure yet if I'm just imagining it, because it seems to go away.

Does it sound like this? Skip to just before the 18 second mark to hear the difference in sound.. Was told its a normal sound with the DI system.

[ame]http://youtu.be/J49X663XeKA[/ame]

Sounds worse than those old Astron II motors from the 80's just like cement mixers :/

Hey guys! Here is the sound. It only happens on cold days, and only after the car has warmed up a bit. I am not sure if it is the direct injectors. I have only done headers and OFT as mods, oh and a catback. . . but that isn't too major. You can't hear it on the outside, only inside.

[ame="https://www.youtube.com/watch?v=cK5Fvh-lvBw"]Scion FRS noise - YouTube[/ame]

I think I have that noise too. Kind of sounds like a diesel engine and only happens after the car warms up and on idle. Sound disappears immediately when you step on the gas.

I think its the dreaded crickets caused by the defect in the fuel pump. If you open your hood and listen, you'll probably hear the high pitched cricket noise.

Sounds like the DIrect Injection, however it sounds awfully fast/loud

Press the clutch !! The sound is gone

OFT does increase the idle to about 800 instead of 600, which might explain why it is faster. The sound is pretty much gone after 1000rpms.