Hi, my son's truck is a 2008 XLT with the infamous 5.4 3v. It has phaser rattle at startup but after.thst it is smooth and runs fine. Recently it ran very bad when my son was driving into school. 3 different cylinder misfire codes along with p0012 I believe. (Happened a couple weeks ago and I didn't save the codes) We towed it to a mechanic and he said he ran a oil pressure test and it tested at 22 psi so the motor is bad. He didn't do anything else and emailed me a quote for 12k. My son and I were disappointed since this is his first vehicle. We decided.to drive.it home because we weren't going to spend 12 on a truck we spent half that to buy. It ran good on the way home. I cleared the codes and nothing has come back. We drove it a couple of hundred miles and yesterday I changed the oil and took the filter apart. Ill post picks of the worst of it. My question is do you guys think its too much and the motor is toast? If not we want to do all new timing, phasers, guides and new oil pump.

 

Many of these engines have been resurrected, as long as they aren't already beyond repair. 22 psi is low, but not terrible according to Ford's specs.
What you would want to do first is check the crankshaft endplay and make sure it's not excessive. Then you could play around with running a thicker oil like 5w40 which should have slightly higher pressure when hot since it's supposed to have higher warm viscosity
If you do go with a timing job and you can do it yourself you can probably do it for $1000 ish and it will take a full weekend of work or several evenings.
Definitely use OEM parts except you can opt for a melling high volume oil pump to make better pressure.

 

My thoughts
2008 model year 5.4 engine
If I were you I would pull the pan and check for debris in the oil pump screen and the sort of cup area directly under the screen. The timing chain guides wear and sometimes pieces break off.
Why do this - First, it pretty easy on a 2wd and takes more effort on a 4wd. Second it may not cure your problem but it will give you an idea of your existing condition.
The stuff in your filter made its way through the oil pump pickup screen and I suspect you have a partially clogged screen. There is a possibility that cleaning the screen and the area below the screen may bring the oil pressure up.
Timing component replacement may be in your future but the above will give you a better feeling for your overall situation.
If your oil is new and you are careful your can save the oil and pour it back in through a coffee filter, probably save you $40.

 

Unfortunately I drained the oil into an old dirty catch so I decided to just put new oil in it. It is 4wd so I was looking at the pan and it doesn't look too easy to pull out. Since it has phaser rattle Im thinking we are just going to put in all new timing, phasers, guides and a upgraded melling oil pump. Probably check on roller followers too.

 

Pan has to come off anyway, just do it as one of your first steps.

 

you never mention the mileage on this motor. What the engine build date ? in 08 there was an updated motor built with upgraded heads/plugs/vtc. it's got brown cop boots.