Looking for some insight. I have a 05 F150 5.4 3v. Truck is in really nice shape and worth running.
I replaced both cam phasers, chains and guides in Nov. Cam phaser noise went away. Now I have this random problem that is a bit tricky to describe.

At idle, the engine sounds fine...a bit of a rough idle. When I rev the engine up ove 1000-1200 rmp I get what sounds like valve train noise or bad timing (ping/rattle) Sometimes the engine will really start rattling and want to stall...i I rev it up the rattle/ping/roughness goes away..almost like there oil needs to build up pressure for the phasers. I just took out both VCT's and cleaned them...both have solid screens and look oh. I did a test on both vct and one is at 9.9ohms and the other around 11.

This winter I first noticed my truck doing this after running on the highway and then trying to back up my snowmobile trailer slowly....the engine would start rattling and want to stall.

My oil pressure gauge is reading above half way all the time. I had put synthetic in my truck last summer and as soon as it got hot...I had this problem really bad....changed the oil back to 5w20 the next day and it ran decent. I am thinking it has to do with oil getting to the cam phasers and the timing going way off.

No codes!

Any ideas???

 

im having the exact same problem on my 07 fx2 5.4 triton.

 

did u ever find out what it was cruzn56?

 

switch to a thicker oil and see if it goes away (like 15w). If it goes away, then its an oil pressure issue and the truck should be deadlined immediately and the heads evaluated for proper oil flow. Don't do like I did and ignore it. Mine did that and had limited oil flow through the heads. I did not know any better and took the word of the service manager that cam phaser noise was normal. When roller tips seized and ate grooves in both my cams it was a new truck from there. I love my new truck, but I only have it due to the expense of replacing the engine in my 08 after i ignored the very sounds and symptoms you mention.

 

15w is too thick for these engines, and just asking for trouble. 5w20 only, especially the 3 valves.

 

yes 15w is too think, but it increases oil pressure and rules it out. It is not meant to be ran for a long period of time. That trick came directly from Ford techs as a means to see if there is an oil pressure issue in the heads. By increasing oil weight, it increases oil pressure to the phaser. If the problem goes away with the thicker oil, then you know you have low flow in the head and immediately stop using the truck until the heads can be evaluated. I was not and am not suggesting simply switching oil. Use as a diagnostic tool only.