Heres your answer.

 

Did you ever solve this problem? I have the same issue. I have a 2006 XL with the same 5.4l motor. I've been dealing with this problem for over a year and have over $2000 invested at the dealer for diagnostics. Not once have I been in better of a situation with my truck since the start. Now after all this, the other day I got my truck back again and they tell me I have .030 play in the rear of my crankshaft and low oil pressure. They're telling me I need a motor replacement. Oh and that it's not their fault and it will cost me $8000 for the motor and labor. After talking to a rebuild company in Detroit called accurate engines they tell me that they had issues with the rebuilt motors that have been getting sent back. They told me they have been working with ford directly and figured out that the cam phasers HAVE to be locked out to correct the problem. After the lock out you can run any oil you want and the problems with the phasors and timing system will never be an issue again. You'll lose 3% of your fuel economy but the power will be restored to your motor. Idk what I'm gonna do at this point because the dealer really should be paying for a new motor after all the money and time I've spent on this issue just to find out I need a replacement. Looks like I'll be going to court

 

What was the work preformed on the truck? Cam phasers and chain I guess.
Ford should have warned you about the other problems that could come up.
Like I posted before the 5.4 is known for taking out the cam journals, plugged oil pick ups, cam phasers, and tensioners. In there great wisdom also used aluminum main and rod bearings. I haven't decided what I'm going to do, I am leaning towards a rebuild. Jasper engines now bore out the cam journals and installs proper bearings and use Molly main and rod bearings. There engines are about 4,000 with core return. To find a good used low k engine there going for 3,000 and up.

 

Just got my truck out of the shop 2 hours ago. I have a very trusted mechanic. It was the throttle body needed cleaned. That's all it was. My truck stalled at stop signs, slow turns, red lights. low oil pressure. Throws a code for crank position sensor, and says unexpected low idle. It was the throttle body needed cleaned. Im so glad I didn't try all the other things I read about. Mechanic would not even let me pay him.

 

I had vct solenoids replaced. They claim they took off my front engine covers and checked the chain guides and sliders but who knows if the actually did. The rest was all just a bunch of scratching their heads and saying I need to change my oil more often. I change my oil every three weeks because I drive two hours round trip for work every day. I use full synthetic Mobil one 10w30. The dealer is also claiming that because I don't use a ford oil filter that I'm the reason this happened. If that's true then shouldn't they have told me this a year ago when I first brought them my truck? I looked into the jasper motors and if love to get one however I talked to jasper three days ago and they said $4800 plus $1000 core charge. I'm also told that in order to change the motor in this truck you almost have to take the cab off the truck. Is this true?

 

Think about this- when you have debris blocking your oil pick up tube, you usually have more pressure when the engine is just started(when warm) and all that material isnt against the suction screen yet. As the engine runs more stuff sticks to the screen and pressure goes down. You also have a tendency to lose pressure with higher rpm. Its been my experience that low oil pressure doesn't make an engine stall.