Okay, for a while my car (89 formula, carb'd 350, emmissions stuff still there) has been making this wierd noise whenever the engine is above like a thousand RPM's or so.....its not a ticking sound, its more of a pulsing sound like those air pumps you plug into the cigg. lighter of a car or whatever.......my only guess is that its something to do with the AIR system, but i've got no idea what it is or how to make it stop!
Any ideas?

 

Start soaking the fittings on the A.I.R. check valves with penetrating oil. B'Laster! PB works great, but even WD40 will work given adeqate time. Wet down the fittings at least every day. After a few days, try removing the fittings. When you get the check valves off the air pipes, you should be able to blow through them in only one direction. Chances are that one of your's is stuck open or rotted out so that air flows in either direction.

 

I'd also check your exhaust manifold or headers if you have them. Do as vader said and spray them down. You may have an exhaust leak.