A friend of mine had an 09 F-150 with the 5.4. At around 90,000 miles it developed a ticking sound.
He brought it to the dealership and hooked it up to the computer and told him he had a cylinder low on compression.
He brought it to me to have a look at it. We found a spark plug that was loose (hand tight).
Torqued it back down and it ran fine, no more tick. Later he decided to change the plugs so he bought the new style one piece plugs and the special tool just in case we needed it.
I changed the plugs in about an hour without breaking any. They were really not too bad to get too.
I hope you get just as lucky as I did.
Oh, the dealership quoted him $2500 dollars to fix the cylinder that was supposedly bad.
