To those that have the duratec "Tick" that is loud and proud at RPM's below 2500-ish Like myself, You probably have some tired bushings in the intake for the mechinisim. Here is a video I thought that might help make sense of what is going on on.

Here is a video of the TICK :
Here is a video of the flappers:
Thought it might be some good info for someone looking. I will be replacing my intake manifold soon, I don't want those little bastards to break completely and fall inside the engine. They are little butterfly valves that operate by vacuum via the pcm. 2004+ duratecs do not have these. Either I'll replace the manifold, or try to remove the flappers (but leave the computer accessories to allow the PCM to stay happy and not throw a code)

 

mine did the same thing for as long as i remember but my intake manifold havd a hole in it so i changed it and it quit

 

Yeah, That is the route I'll probably take too.

 

Interesting. Removing the flappers does not mess with the engine's performance?

 

I know that +04 intakes don't use those flappers, so I guess not. I was curious, so I unplugged the vacuum line to the actuator (the one you would pull if you were diagnosing this noise) and drove it around. Felt exactly the same, I couldn't even tell. That, and the vacuum lines that go to the actuator tend to be a fairly common problem (especially the hose with the 90 degree bend) that throws up a check engine light. When this is on, the runners / flappers aren't working and from what I've read nobody has reported any driving differences with it on.