2006 E-250 5.4L 2v with 164,000 miles
I recently purchases this, the van seems very peppy on take off, but with a minimal load, 800- 1000 pounds the van seems to lack power pulling hills or accelerating. I did a full tune up when I purchased it, Motorcraft plugs, new boots and springs, sea foam in the fuel, pcv valve air filter etc. I did do the fuel filter, and it was pretty nasty as well. I changed the stock tire size of LT 225 75 16 to LT 245 75 16's I had a good set from my old 1 ton van with the 5.8L and the tires on it were garbage, is there anything I should look for? I do have a snap on solus ultra scan tool, so that should not be a problem. It was suggested that these 2v engines are gutless with a load, but I cant just buy into that. I was also told that I could get a programmer to get a little more out of the engine, but I have never dabbled in this area, and care not to unless an option. This van will be a service van and with custom shelving, and tools I suspect my average load will be around 1000-1200 pounds. I just have a hard time believing my 95 E-350 with a 5.8L and 190,000 miles should have more power, although that proved to be a Great Engine for me.
The 5.8L and 5.4L are very different engines. The 5.8L made torque down low, made it seem effortless. The 5.4's are rev happy, especially if you still have the 4 spd, which i think you do in that model year. Peak power is like 4200RPM if I remember right, with 1200lbs you'll have to keep her revving high to move it around, but just do it, these engines like to rev. They don't lug at all like the 5.8L.
My 06 E350 extended 215,600 is along way from a power house. Drive by wire leaves alot to be desired as well. Not sure how much weight is in the back, but it's pretty full of telephone equipment and wire plus tools. Loves the higher RPMs.