I have a 2008 6.4 powerstroke with 75000 miles. When I start it there is a noise like someone knocking from under the dash near the front window. I believe this is the drive in the ECM Does anyone have any experience with this

 

6.4L Power Stroke Diesel - Ford Truck Enthusiasts Forums Here is a link to the page for your engine. Probably best to ask there.
Good luck.

 

I bet that is actually your blend doors for the HVAC.

Try shutting off the controls for heating/ac and then listen.