Nope - an incident was real as reported here. I can only vouch for what I can see at the URL for WSJ and as I'm not a WSJ subscriber I take it on faith that the rest is accurate? I guess other news outlets will have their versions soon enough? Most of the text below came from this page:
"Oil Leak on One Plane Leads to Inspection of 104-Jet Fleet.
The Pentagon temporarily grounded the entire F-35 Joint Strike Fighter fleet at the start of the weekend after one of the advanced jets suffered an engine oil leak and declared an in-flight emergency.
While the suspension of flight and ground testing on Friday was described by F-35 program officials as a precautionary move, it is the second time in 16 months that engine problems have grounded the entire fleet. It comes just two weeks before the plane is due to make its first international appearance.
Engine maker Pratt Whitney, a unit of United Technologies Corp., said most of the 104-jet fleet had been cleared to resume flying by late Saturday following the safety inspections mandated by the F-35 managers on Friday. The F-35 program office said these revealed potential problems on two more jets.
The incident on June 10 involved an F-35B jet, which can take off and land vertically. The pilot declared an in-flight emergency after being alerted to an engine oil problem, and landed safely back at base at Marine Corps Air Station Yuma in Arizona.
Pentagon officials on Friday ordered engines on all three models of the F-35 to be inspected before they could resume flights.
Pratt Whitney said in a statement that it was working to identify the cause of last week's problem, with jet-by-jet inspections taking around 90 minutes each. Program officials have pointed to problems with an oil-flow-management valve.
The F-35B is one of three variants of the jet built by Lockheed Martin Corp., and scheduled to be the first to be declared combat ready. Program officials last week expressed confidence that it will be ready for the Marine Corps as scheduled in July 2015."
F-35 Fighter Jets Temporarily Grounded by Engine Problems - WSJ "...DellaVedova said the source of that F135 engine oil leak appeared to be a supply line to engine bearings and a fitting that separated from the body of the valve in question. It was not clear if the issue was maintenance-related."