Hello looking for some advice for trouble shooting,
truck has 165k, At around 150k replaced- Upgraded oil pump, water pump, cam phasers, timing chain, guides, tensioners, radiator, coils, plugs, battery an FPDM. Truck ran GREAT for about 9 months an a few days ago was in a drive through and out of nowhere truck just started shaking and wouldn’t run at idle. Set a cylinder #2 misfire code. Swapped plugs an coils around an got same code, pulled fuel rails tested injectors an took noid light to injector plugs which all were good. Going to test cylinder pressure when adapters arrives. Guessing if rings aren’t bad might have a valve stuck or bad seal, cylinder that is setting code has oil on plug.

 

After testing compression maybe that will tell you something. The next thing I'd do is pull the valve cover and see if you popped a cam follower out of place..

 

yes I agree, I am hoping to track down a compression tester Monday, I’m hoping the rings aren’t bad

 

oil on plug usually means piston ring failure

 

I have an 2007 F-150 with 5.4 as well. Two summers ago it idled poorly, set off codes. Shop replaced MAF and the codes went away until the next summer. Have read of this problem several times for this generation. Be sure your a/c compressor isn't laboring and dragging down the engine. Mine only has a little over your current mileage and never had any kind of serious repair other than the a/c system. Runs great at the moment.

 

Ran a compression test on cylinders today, all were around 110 to 150 except #2 which is where I got my misfire codes from originally. Test was dry but didn’t get a bit of pressure which if rings were bad I would image I would get some readable pressure. I am going to pull valve cover next, guessing valves are stuck open, will retest Cylinder 2 with oil before pulling apart valve cover.

 

#2 cylinder could have tossed a rocker arm. Fordtechmakuloco has a video where hes diagnosing a noise, takes off the valve cover to look around and at first doesn't see the rocker arm sitting in the corner. It's amazing how these engines can run like that.

 

#2 cylinder has stuck intake valve, rocker arm broke off, Thankfully cylinder top looks undamaged from valve. Pulling cylinder head today

 

Anyone know if the timing chain should have slack in it? Passengers side has a good amount of play in chain, Replaced it all about 10k miles ago but don’t recall if it has slack until tensioners are engaged with oil pressure. Will get a pic when I get to it today.

 

There should be no slack at all. Even if you got the crappy plastic ones (which you probably did), they should still keep tension even when the engine is off. You should have gotten the metal ratcheting tensioners, they don't require oil pressure to keep the chains tight.