The Ford Triton 5.4L 3 valve engines found in the Lincoln Navigator, Ford Expedition and the F- Series Trucks, have an inherited problem with seized spark plugs. Engines with over 100,000 kms will generally suffer a number of broken spark plugs. Due to this ever growing problem, The Spark Plug Doctor is offering our customers a $600.00 Maximum service charge to remove 8 broken spark plugs. If you have less than 8 broken plugs, call us for a quote. To schedule an appointment or for more information on our services, please feel free to call. THE SPARK PLUG DOCTOR FRANK McCARTHY 519-969-9278 Spark plugs in the three valve version break in a variety of places. Each type of break has to be carefully assessed first, in order to determine the proper method of removal. The first image on the left is the best possible break - everything comes out of the hole except for the ground portion of the plug. In the next image, the ground and ceramic portion remain in the head. The third image is missing the electrode as well. Fourth image is the worst case scenario - threaded section separates as well - NOT A GOOD DAY !