My Mkx recently started having an issue with an hum/whine when going from idle around 40 KM/h to about 60 Km/h. Issue seems to be intermittent and most frequently occurring on more frequently when road is on a inclines but also sometimes when flat. Can't pin point source of the noise but sounds like it’s from engine or transmission. Car's acceleration rate slightly degrades during noise and picks back up again. Attached is a sample audio of the sound in question taken from my cell phone placed on the dashboard with all windows up. Sound in question is around 9 second mark of the audio. Sorry for the poor quality since it was from a cell phone mic.
Prevision similar thread seem to indicate possible AC compressor for fuel pump issue.
http://www.fordedgeforum.com/topic/10637-engine-humstraining-noise-with-ac-on/ http://www.fordedgeforum.com/topic/3664-high-pitch-whine/page-2
Would really appreciate some feedback on what could be causing the sound before I take it to the dealership since they might not be able to easily reproduce it.
2011 Mkx Whine.mp3
