Weird Weird Weird
 

Started my 2014 Shelby and moved it about 100 feet from front of house to garage. Turned off car and closed garage door. Got out and heard loud humming sound like something was running. I put my ear to the exhaust area and what ever it was it became louder the closer I got to the pipes. Does anyone have a clue what could have been on. I opened the door put the key in and started it. Waited about ten seconds and turned it off. It has never made that sound before or after I ran it for those few seconds. Does anyone have a guess at what could have been running?

weird

Mouse in the exhaust going nuts from the start! ... Lol.. I had a similar thing happend to my Nissan 2012 Pathfinder I pulled it into the garage and shut it off maybe moved it 30 ft and went inside. 5 min later I needed something in the garage and could hear a weird humming? I tried to find the source for 20 min then it just stopped? That was 3 months ago and it never re appeared.

Have had that complaint at work a few times from customers. I do not work for Ford. But our cars use a vacuum pump to test the Evap system. Probably what you were hearing assuming Ford uses a similar setup to test for Evap leaks.