2003 ford expedition spark plug blew out of head at 85k miles. ford dealership acknowledged that it sees 2 spark plug blow outs a month and ford is aware of the problem in 2003 expeditions. repaired with a ford fix - heliacoil or liner installed into head for damaged spark plug. for true fix, ford needs to replace the head and spark plugs to ensure that other spark plugs don't come unthreaded as mileage increases. *tr