Fluid Leak Problem for Ford
Some 2011-2014 Taurus, Explorer, MKS, 2011-2013 Edge, MKX, 2011-2012 Fusion, MKZ, 2011-2012 Flex, MKT, 2013 Flex and MKT vehicles equipped with a 3.5L GTDI engine may exhibit an occasional fluid leak coming from the rear differential vent cap in temperatures below 32 degrees.
If only a light residue is found around the cap, consider this as a normal condition. If a substantial leak is found, remove and discard the vent cap and install a new rear differential vent cap and clean off any remaining residue. New caps are available as P/N DB5Z-4022-A.