Hello all
I have a buddy that owns a 07 f-150 with a 5.4 and it has two cylinders with very low compression. The truck Is running very bad and after doing some research online i have found it is a very common problem. I did find that alot of these motors had problems with the cam phasers or somthing like that im not to sure what those are or what they do but from what i have read when they are bad it makes alot of noise. His truck however is not making any strange noises its just running like you unplugged two of the coils. He has talked to a few mechanics that were very familiar with this problem and both told him he would need to replace the entire motor. However none of them have torn into the motor its just what they said after hearing the symptoms. the truck only has 102k on it and i just have a hard time beliving the block and entire lower half of the motor would need to be replaced if its just a head problem. can this issue usually be fixed if both the heads were replaced with new or re manufactured ones?? Maby i am wrong or don't fully understand what is going on with these motors. I do have alot of experience with working on cars and trucks but never worked on one of these motors. any info would be appreciated thanks in advance

 

Check the number #4 & # 8 spark plug first. Mine came out using only the extension and plug socket by hand , spun right out. The 5.4 is notorious for loose plugs, also, find the article on the falt the plugs have. You need to put the new redesigned plugs in asap.
The problem(they break off))??
You'll probably want to replace the two coils if you find this is the problem.
Story after story of loose plugs, cam phaser noises, when the motor was redesigned the oil galleries weren't enlarged so you have to use 5-20w oil of your upper end valve train will not get enough oil and BYE BYE motor. And thats about $6500-$12000
But, hey,' my ford f150 5.4 triton is awesome, as long as i don't crank it.

 

Mine dropped a valve and the piston shoved it back into the head and jammed it in there. Throwing the rocker arm and spring into the head cavity. New engine reqd! These engines have serious problems that lend to valve train failures. Some new and re-built engines are improved. I drove mine on highway only and changed with 5-20 synthetic every 3 to 5k. I hope to replace my engine in the spring. But then again, I may just send it to the parts man!