Ticking sound, not A/C compressor or engine valves etc

Seems to only happen when the car is hot. It is not cams or valves etc, it's not coming from the engine. The ticking is steady and always the same BPM, and it happens intermittently. If I hear the ticking and I rev the engine, that usually stops it but not always. My first though was it has some kind of debris in the intake or EGR system but i'm pretty much at a loss to the cause. All i know is it isn't an internal engine noise, nor does it have anything to do with the AC (happens with the ac off and on regardless of compressor function). after driving it and parking it and getting out it does it the most. it will click for about 5-10 seconds then stop for 15-20 seconds, and then click for 5-10 seconds again, over and over. the ticking is pretty fast.

https://www.youtube.com/watch?v=1U6WfN1YJs8

This sounds about it. the speed of the tick never changes. that's about all i have. also, its not the radiator fan.