Engine was missing when trying to accelerate or pass vehicles. Dangerous situation when trying to pass on highways and interstates. Took 2006 Lincoln Navigator in for new spark plugs. Dealer said all 8 plugs broke off and one damaged the head and now need new head due to broken spark plug. Cost will exceed $3,000. Spoke with 6 local mechanics and all agreed this is a big problem. Why should I pay for Ford's faulty design?

- Hinton, IA, USA

2006 Lincoln Navigator, 60,000 miles on car. Car shut down after giving an engine failed safety mode error on dash while on four lane busy highway traveling 40-45 mph. Coasted to side of road (no berm available)... waited 5 minutes. Restarted car and limped into gary yeoman Ford dealer. I was told the throttle control body & motor asy #3L3Z*9E926 was bad and was not covered under the extended warranty I purchased on the car in 2009. Repair bill was $900 out of pocket. Checked online and this is a known issue for Ford Expedition & Lincoln Navigator engines and yet Ford does nothing to fix. Does someone have to die to get Ford to repair these defective parts? nothing more dangerous than a car that shuts down in heavy traffic traveling at high speeds.

- Florida, FL, USA

Engine shut down at 45 miles an hour. Fail-safe light illuminated followed by a loss of power steering. Coasted car to the side of road and turned key to off position. The engine immediately restarted with no other problems. This car has 79,000 miles on it and I have owned it since new. This has not happened since the car was new. The dealer took the problem seriously, but can never find a problem. It seems to be a computer problem with the fail-safe mode.

- San Antonio, TX, USA

The contact owns a 2006 Lincoln Navigator. The contact was driving approximately between 40-45 mph when the safe engine mode warning light illuminated and then the vehicle immediately stalled. The engine restarted and resumed operation. The vehicle was taken to the dealer five times regarding the similar failure. The technician reprogrammed the computerized system software and the fuel pump was replaced at a different time. The failure persisted after the repairs. Also, most recent the temperature warning indicator illuminated during the engine malfunction. The vehicle was currently at the dealer for diagnostic testing and a trouble code was not detected. The dealer was unable to locate the problem. The manufacturer had been notified in which there were no resolutions. The failure mileage was unknown.

- Butler, PA, USA

2006 Lincoln Navigator. Fail safe mode comes on while driving and shuts vehicle down. This has happened twice and also exact same incident to friend in different state with same 2006 Navigator. Decided to report after I called Lincoln and they had record of my call in December 2009 and January 2010 but no record of the work performed to correct the problem or the dangerous incident. It happened again September 23, 2010 after it was supposed to have been fixed by changing a sensor. This is extremely dangerous!! car shuts down and my wife was almost rear ended at highway speeds. On google search of "Lincoln Navigator fail safe mode problems" there are 1380 results. Goes to over 2500 when 2006 is removed. During first "fix" Ford dealership replaced a sensor but the details are not documented in my file on the Ford/Lincoln computer system. This could be how Ford/Lincoln is avoiding a major recall for a extraordinarily dangerous problem.

- St. Augustine, FL, USA

2006 Lincoln Navigator, 50,000 miles on car. Car shut down after giving an engine safety mode error on dash while on four lane busy highway traveling 40-45 mph. Coasted to side of road (no berm available). Cars racing by. Waited 5 minutes. Restarted car and limped into team Ford of marietta Georgia dealer. I was told the throttle control body & motor asy #8L3Z*9E926 was bad and was not covered under the $1,000 extended warranty I purchased on the car in 2006. Repair bill was $800 out of pocket. Checked online and this is a known issue for Ford Expedition & Lincoln Navigator engines and yet Ford does nothing to fix. Does someone have to die to get Ford to repair these defective parts? nothing more dangerous than a car that shuts down in heavy traffic traveling at high speeds.

- Roswell, GA, USA

The contact owns a 2006 Lincoln Navigator. The contact stated that while driving at approximately 40 mph, the vehicle suddenly stalled and crashed into the rear of another vehicle. The vehicle was taken to an authorized dealership for a diagnostic test but the dealer could find no problems. Another dealer informed the contact that the power steering, transmission and engine needed to be repaired as the steering also malfunctioned. The failure mileage was approximately 12,000. The current mileage was approximately 42,000.

- Gainesville, GA, USA

1: 10/19/08 I was driving 70+mph and all of sudden car gives an engine failure/safe mode signal which locked wheel, not allowing acceleration. Once able to get to side of the road, I had to try at least 2 times until finally car turned on. It was towed and dealership could not find any problems. 2: 11/16/07 started car drove about 2-3 miles and then when I had to restart the car, it did not come on. It was towed and battery was replaced 3: 7/16/08 turned on car, drove for almost 2miles, stopped at a light and when I had to accelerate, the car gave me a engine failure/safe mode signal. Dealership could not find anything wrong with it.

- Sanford, FM, USA