Just got my truck about a month ago; 2008 F150 5.4L Flex Fuel FX4. It has 34,000 miles on it, lift kit, new tires and wheels. Like the title says just surpassed 1,000 miles driven. As I was driving home from work in traffic, everytime I was stopped my engine would sound like it was about to quit. Between 750-1200 RPM's the truck would knock like someone stuck a stick in the middle of the engine. Took it to a family friend who is a mechanic who said my cam phaser went out! Just letting everyone know that this can happen at anytime and let me tell you it sucks! Now I'm driving a loaner Ford Focus from the dealership that I bought it from (thank god they will fix it no matter what's wrong with it)! I'm just glad I still am under warranty...if anyone has questions about the noises are the readings it gave out just ask I can try to explain it the best I can!

 

Tell the dealer to change the plugs under warranty or you could be paying them massive amounts of money to do it. $700-$1200 for plug replacement by dealer. Do it sooner than later and save yourself alot of hassles.

 

Why would the dealer change plugs under warranty.? They are not that hard to change with the proper tools.

Hope they get your truck fixed up right. Always sucks when you have to drive a small car.

 

Apparently you're not familiar with 5.4 plug issues. Even with the proper tools, if the original plugs are still in there, it's hit or miss whether they will come out in one piece.

 

Thought this issue was fixed post 2007 anyways....OP should be in clear as far as the plugs go if I understand it all correctly

 

The plug problem was throughout 2008 in 2009 they changed

 

Only very early 08's, not all 08 models. mine has one piece plugs. There is a engine build date sticker to refer too and also if your coil caps are brown that means one peice plugs. Black caps are the dreaded two peice plugs under them. I posted more info in the plug sticky thread. Gatorb8 has great facts too about plugs.