So, we have a '11 Flex Limited Ecoboost, ~58k miles. Bought it around 50 as a CPO. Had some issues with stuttering on long acceleration, but new sparks fixed that. Had a hunch that the prior owner hadn't been rotating the tires correctly due to wear differences, put new shoes on and and got everything aligned.
Just a few days ago, I noticed a strange sound like a dangling chain bouncing along pavement from under the car at low speeds. No dangly bits making the sound that way... at first I was nervous about a disintegrated e-brake (fairly common on my prior cars), but it seems we don't have drum-style parking brakes based on some googling I did? So, now I'm worrying it's something worse, like a broken tooth rattling around inside the differential. Noise is definitely rid to movement, not application of throttle, and is louder when moving backwards. Very noticeable at "driveway" speeds, but seems to go away at higher speeds.. which is what makes me think centrifugal force keeping broken parts pinned to the outside of a spinning chamber or something.
Anyone seen this before? Going to try to get a dealer appt as soon as I can, but the only one near me without scathing reviews seems to pick up extra business because of that fact, so it may be a few days before I can get in.
