I have a 2013 1.6L EcoBoost Fusion with just over 45.5k miles. Recently it has started to exhibit an intermittent steering wheel jerking when I begin coasting. It only occurs after 30-60 minutes of highway speed driving, then occurs at almost any speed upon removal of my foot from the gas pedal. There is an associated rumbling noise in the front end when the steering wheel twitches/jerks. It sometimes occurs during acceleration and during braking, but mostly during coasting (no gas, and no brakes). Sometimes this results in a pull to one side or the other but it is not consistent -- sometimes no pull at all. The steering wheel will move between 5-15 degrees when this happens. I have taken it to the dealer and an independent repair shop -- neither can get it to do it while they test drive it (they don't drive it long enough under the conditions mentioned above) and no codes in the computer.
This is not the typical out of balance or out of alignment problems -- very familiar with those symptoms. Sometimes it reminds me of the digital nature of ABS pulsing during heavy breaking. The frequency (cycles per second) of the twitching and rumbling does appear to be loosely tied to the speed -- lower speed, lower frequency; higher speed, higher frequency.
I'd appreciate any feedback wrt similar symptoms