To further expand on Osprey's thought, the Cam Phasers are notorious for failures on these engines. It's not skipping a tooth, per se, but it sure feels like it.

Two things can help identify this issue:

1) Startup clatter - When starting the engine, the cam phasers will clatter loudly and it takes time for the oil pressure to build. Even after running, the phasers will still clatter a noticeably at idle.

2) Bearing "dust" in the oil - After running for a few minutes, pull the dipstick and check for aluminum or bronze "dust" or "glitter" in the oil on the dipstick. This is especially noticeable if the oil has 2000+ miles on it. Any glitter on the stick is a serious problem.

As I understand it, the camshafts are the first components to receive oil and any problem with the cam phasers causes poor lubrication to downstream components. If the phasers go out, the crank and rod bearings are not going to be too far behind.

I really am not trying to scare you with this information and it's quite possible something as simple as a bad O2 sensor or something similar that's causing your drivability issues, but it's definitely worth taking a look just in case.

I hope this helps.

Thank you, Bill, for clearing up my idea.

Coming from over 35 years of working on engines from a 59A flathead in a '37 coupe to today's modular engines, I knew what the symptoms sounded like, but wasn't sure what exact component was the culprit. Hearing about this problem makes me even more leary of the 5.4 3V and the cam phasers.

The more I hear about what can go wrong, the more nervous I am to take my truck out in the "bush". Let's see, we have cam phasers (sounds like something out of Star Trek), fuel injectors, COPs, plugs that fall apart when removed, a fuel pump driver module that likes to swell up and crack, any number of sensors that can all go belly up at any time, and, an electronic brain that might develop a crack in a solder joint which would render it useless.

Wish I had an old WWII Army Jeep.

- Jack

Jack,

The "electronic brain" issue only seems to be a problem in the 6.0L, and only with specific calibrations. However, the rest of your concerns are entirely valid for your vehicle, although I doubt any would leave you immediately stranded. Most of them develop drivability symptoms over time and give you fair enough warning.

As they say, the more complicated you make it, the more things there are to break. :shrug:

It all makes me long for the days of the carbs and HEI distributors. No ECMs, no O2 sensors, no injectors, and chips were for consuming with dip while watching sports on TV. Why, I can remember when you could open the hood and actually see all of the engine!

Of note: In the original post he mentioned the cam phasers had been replaced already, perhaps this could be ruled out. .....unless there has been enough contamination of the oil to plug them up, or low oil pressure to begin with?
The sound he hears certainly seems consistent with a plugged cat or restricted fuel flow, but some of this is replaced also. What are we all overlooking?

Recap
 

iiiiii.

Sorry, MAF readings.. not MAD readings.

update
 

iiiii

If you're in 3rd gear, with the Torque Converter locked, the ISS should match the OSS. If not, something's "slipping". So, monitor the "Comm Gear" PID, ISS and OSS to check this. In 4th, the OSS would be higher than ISS with the TC locked and in lower gears, the OSS will be lower than ISS.

Again though, the TC has to be locked, because if it's not, they will always be different.

I'm puzzled when you say it won't shift to high gear (4th) when cruising. Do you mean if you are holding a steady speed at say 60 mph on a level highway the truck never gets into 4th gear? If that's the case, something is badly wrong.

- Jack