One problem related to engine has been reported for the 2003 Lincoln Navigator. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Lincoln Navigator based on all problems reported for the 2003 Navigator.
My 2003 Lincoln Navigator ultimate @ 84,000 miles blew 2 spark plugs through the aluminum head of the 5. 4 liter triton engine. It is my understanding that this aluminum head has been redesigned by Ford and that there is also an after-market fix to this increasing problem that re-threads the spark plugs, but that said fix also gets forced through said inadequately engineered aluminum head. For refuses to pay for the replacement of said head and said repair is estimated in the thousands of dollars. I replaced the melted coil and barely was able to thread new plugs into place, but I am concerned about being stranded somewhere in my car. I think that Ford should have to recall all of these engines and replace the old heads with new, better engineered heads.