Review on Motorcraft SP509 1840 EIGHT PCS SPARK PLUG MOTORCRAFT SP509 FORD EXPEDITION LINCOLN NAVIGATOR V8 by Aaron Webb

Use these on mid 2008 and newer 5.4 valve engines. Ford redesigned the heads on this engine to fix a bad spark plug issue. The new heads are great and were introduced in May 2008 for 5.4 3 valve engines. You can tell if you have new design heads by pulling on one of the coil packs. If the boot is brown, you're lucky, you've got new heads. If the boot is black, I am sorry to say that you have an old head design. This requires a different spark plug and you must be very careful when removing it to avoid damaging the spark plug extension in the cylinder head. This can be a very expensive repair. There are some good YouTube videos addressing this issue.