Since I've been on this fourm I've read about all the problems these engines have had such as cam phasers and the two peice spark plugs. I was just wandering if Ford work out the bugs on the 5.4 by 08 or do I still need to worry about such things? I bought a used Lariat with 84000 miles. I don't hear any ticking noises coming from the valve train area but there is a soft knocking noise that I can hear while the truck is idling. As far as I call tell it qiuts when you give it some gas while in park and I don't hear it while driving down the road but I can hear it if I'm just rolling along and the engine is idling.

 

By 08 most of the phaser issued had been resolved, but that doesn't mean that they couldnt crap the bed at some point...afterall it is a mechanical part and failures do happen.

You shouldnt have a problem with the plugs. There was a head redesign in 07 that has been reported to have fixed the plug issues.

Drive it, enjoy it, and keep it on a regular maintainence schedule with the FL820S Motorcraft filter and you're good to go!

 

Unplug VCT Solenoid sensors they are on each side sticking in the valve cover, one is located directly under the power steering reservoir. If the knocking stops its the VCT solenoid sensors. Phasers will tick all the way up to 1000-1200 RPM and disappear. Most likely a VCT solenoid. These motors do have a tad bit of a clicking sound as their running and there is a 'slapping' sound at 1000-1200 rpm's this is 100% normal for these trucks even a TSB about it.