hey i took my car out today between classes, and took it up on the highway for a little fun, and when i got back it was making this horrid clicking noise that changed with the rpm. i have no loss in power or anything. i popped the hood and i think the sound is coming from my #2 injector. will a failing injector get really loud? its pretty annoying.

 

Valves

 

With the car idling, temporarily unplug the injector. If is is the injector it should stop.

Next listen for the lifters in the area.

Finally, while it seems drastic, it is an option........On one of my mustang motors i ingested a small piece of metal left behind from a broken wrench. Once I hit 6K the airflow was enough to suck it through the motor and after bouncing in the CC for a while, it became a permanent part of the piston and beat the hell out of my aluminum head. It was a real nasty noise but otherwise the car ran fine. (in your case a weak valve spring at high RPM's could have caused a piston to touch a valve but it probably wouldn't run perfectly.)

 

A liftter sounds like a tap, injectors are more of a click. Like Jeremy says, unplug the injectors to isolate them.

How's your oil?

 

oils fine. the noise, however, is gone after sitting a few hours :/

 

Lifter.

 

no way it can be a lifter, ive heard lifter slap before (not on my car thankfully), its definitely a mechanical click. or was, i drove it this morning again and it was fine just like last night.