I looked thu what seems like 100s of post about 5.4L 3 valve engine noise and haven’t seen problems that match what I’m experiencing.
Engine noise sounds like it coming for passenger side. Sounds like it could be an exhaust leak, or tapping, or possibly a pre-ignition ping. Also it seems to lack power and seems to be using more gas than normal (what ever that is). The noise is not present a idle or when cruising on level pavement, but as soon as I apply a little throttle it shows up. It’s very noticeable when I tow my boat ~ 6,500 lbs. At higher RPMs I don’t hear it, but it may still be there. I’ve listened to the engine at idle with a stethoscope and I don’t detect any unusual sounds.
All the cam phaser problems I’ve read or seen on YouTube indicate the sound is present at idle. Which is not present on my engine.
No engine service lights have come on.
I’ve checked as much of the exhaust manifolds as possible (without unbolting covers etc. and didn’t find any cracks.
I checked the coil resistance; the primary were all the same (I think about 1.1), but the secondary resistance was 5.43K on 6 of them and 5.36 on the other 2.
I’ve run OBD2 Scanner and found no misfires on any cylinder or any other problems.
A couple of months prior to this showing up, I replaced the spark plugs. Since then I’ve gone back and check and retightened each one and applied the dielectric grease to the boots. All seemed fine.
The fact that it doesn’t show up at idle or when just cruising has me stumped.
Recent oil change Mobil 1 5-20. Previous owner indicate always had synthetic oil.
Any help would be appreciated.

 

Does yours have a PCV valve over in the passenger valve cover? If so check that for damage.

 

Yes it does, I'll have to check them. How will a bad PCV affect it?