Here's a tough one!

Hello everyone - I have a 2005 F150 5.4L 3v, 198,000 miles. I had the famous cam phaser tick. 3 weeks ago I tore down the engine and found a bad cam phaser (passenger side) and bad timing chain tensioner (passenger side). The passenger side chain was actually hitting the timing cover. I did a complete timing job: Replaced timing chains, guides, tensioners, both cam phasers. Truck started right up and ran great - no noise at all and more power. About 3 weeks of perfect running, the truck started making a rattle noise ONLY when starting - The truck throws a P0011 code. But other than that - it runs great. Idles fine. No other codes. The rattle (or chatter) is very short and goes away in a matter of seconds (almost seems like it disappears when the oil pressure comes up a few seconds after starting). The problem is something is defiantly wrong (because I hear the noise) - and the only clue I have is the P0011. I would like to get your thoughts on what to try or check before I tear into the engine a second time. FYI - the inside of the engine looked normal for a well maintained 198K mile engine. No broken guides or plastic in the oil pan. Mobile 1 full synthetic and Motorcraft oil filter has always been used. Any ideas would be greatly appreciated.

If you didn't have the motorcraft oil filter, I would have said that was it. A lot of guys are doing a mix on the oil, 5 qts of 5-20 and 2 of 10-40 for this start up noise.
Did you replace the VCT solenoids? Mine had something go thru its screen and knick the internal shaft. So it didn't fully move as it should. The solenoids going bad can cause the P0011 and P0012 codes as well as the sensors going bad. You could try unplugging the sensors and see what that does for you. For the solenoids, here is a video a guy did on replacing them on YouTube.
https://www.youtube.com/watch?v=YUZR3J5ALbk

Hi - I did not replace the solenoids or the sensors. It only happens when I first crank the engine after sitting a ling time - only last a few seconds but causes the P0011 code. How does the sensor detect the over advance position? (does it use the tabs on the cam phaser?)

If the cam phaser was actually in an over advanced timing position - I would think the truck would have trouble starting or idling - which is does not. It starts fine and idles / runs fine. Just makes noise when first cranked and throws the P0011 code. No other codes.

I say swap the sensors. If it is just one of them, then the code will change to a P0012 for the other side. Quick, easy and cheap way to see if it is a sensor. If no change, try unplugging the solenoids before the cold start and see what happens then.