So mine started making this noise yesterday. Noticed it when I pulled in my shop. Car was at normal temp. 20000 miles. Just changed the oil and used Ford 5W50 full synthetic. All previous changes were at the dealer so hope they used the correct oil. BTW on the lower radiator cover in front of the oil drain plug it states "Remove when changing oil" which I did but I could not find anything to drain. Anyone know why Ford would want you to drop that cover?