I heard it just recently, its like a ticking or tapping sound that ONLY occurs around 2500-3000rpms. And it only does it occasionaly. I dont know if this could be related, but i also have an iratic idle, it will go down to about 500rpms and be rough but if if rev it up and let it go back down to idle then it goes to normal. It also only does this occasionally. im not sure what it is. I thought the idle problem could just be the throttle sticking or the tps sensor going, but im not sure.

 

btw, my car runs great power wise. Like a rapped ape. I just went out and popped the hood so i could listen to the engine and it was pretty quiet. I even pulled on the throttle and revved it up a bit and i heard nothing. Im stumped

 

Whats all done by your car, when i changed the spark plugs in my 94z made a hell of a difference, id find a mechanic to put it on the scanner, theres a number of things it could be, as for the rattle i dunno could be a loose rocker or what not, Im fixing to change to a MSD 6A hopefully will cure some of the idle trouble you might consider changing too.