2004 FordF150, FX4, 5.4l V8, with 3 valves per cylinder

[vrmnthntr]

As everyone has already said. Spark plug problems, cam phasers, and manifolds.

We have a 2004 with 81,000 miles. Nothing but routine maintenance. There is the tick from the cam phasers. Original plugs are in it and won't come out until they have to.

 

[Diamondpilot]

He has no clue. I know of a dozen or more with 175,000 miles or more. My BIL has a 09 F150 with 180,000 miles. He broke 2 plugs changing them but other than that nothing else. My Sister has a 07 Expedition with 150,000 miles and not a single issue but she has had both power front windows changed and a power mirror that stopped working. My neighbors son has a 04 F150 with 225,000 miles. To date the biggest issue was the tranny had to be rebuilt. Cost $1,200 with all the updates.

Yes, plugs and cam phasers can be a issue but routine maintenance as with anything helps.

 

[civilian]

Otherwise it's a pretty stout motor, but, thirsty. Expect low teens for mpgs

I just brought it from DC to Northern Michigan on Monday, running speed limits+ 3 mph and got 15mpg for almost 500 miles. 36 gal sure travels a long way between fill ups. My 2007 Tundra with the 5.7L V8, got high 16 almost 17 mpg on the trip out. But only 26 gal tank.

Thanks for the comments. Jon

 

[TractorGuy]

Have two of them in the family, 05 and 07. As stated the plugs are problematic, however if they've been changed with the updated plugs you'll be fine.

Cam phasers can act up and manifolds have a tendency to warp, they actually aren't that hard to replace as long as the bolts don't break.

I like them, much better engine then the 4.6L.

The only way to "update" the plugs is to change the cylinder heads. The pre 2007 engines were the ones that could break the plug shields off when the plugs are removed. The newer style had completely different heads.

I have a 2 valve 4.6 with 157k on the clock that has been bulletproof. It has spent a good bit of miles pulling a loaded car trailer. Changed plugs at 100k with no issues.

 

[TMGT]

The change to a more traditional plug was made in late 07 for the 08 model year. There is an updated plug for the 04-07 3v. It uses a stronger one-piece lower section.
As for the 4.6, there are a lot of them running and they are good engines, however from experience working on them most of my life in the automotive industry, the 5.4 3v seems to hold up a little better, especially in the truck and full size car applications.

 

[sld]

The updated plug is one piece instead of two piece. No more breaking on removal.