2013 FLEX "puttering/jerking", grinding sound...

Does this "loud grinding sound" continue while vehicle was stopped with engine running? .. IF yes, then the problem is under the hood! .. Suggest having car savvy personnel with a well trained ear listen to the engine... Test drive 'IF' necessary.... Otherwise it's just an Internet forum guessing game !

Hey Jmopain – if the grinding sound is during braking, it sounds like a reported problem from other with the Ford Flex. Check it out here: http://repairpal.com/brake-noise-front-grunting-grinding-030 Good luck!

This happened to my 2010 eco boost. Shortly after the ptu ( power take off) blew up. Part was replaced but still had issues. Took to second ford dealer seems first dealer that fixed ptu forgot to fill my transmission fluid back up. I was running it on 2 quarts when it should have been on 8 quarts. She's never been the same.