i'm about to buy a 2001 f150 supercrew 4x4 5.4l, has had full synthetic from day 1 and only has 115k miles. was curious if anyone knew of any problems i might be coming up on soon if there are any that happen this early in the trucks life.

 

Not really. You're buying the same truck I drive and have no real issues. I aam going to have to put an IAC motor in it, but that's nothing major. I do occasionally have the PATS key problem but it's under warranty and really not a huge problem, more annoying at times. All in all, you're buying an awesome truck that will take anything you can throw at it while still being comfortable in a vehicle that looks great.

 

Could need all 4 ball joints and/or tie rods if they are original.
If it hasn't had the plugs changed, it's probably time.

 

Check for engine noise on start up,make sure it is cold(Google 5.4 Triton engine noise) 2 valve,2001 has no cam phasers

Rust in the rocker panels and bottom sides of rad cradle supports,these are hard to see.
Broken exhaust manifold studs usually passenger side rear.

Spark plugs are know to come loose
Coil on plugs are known to fail when in OD,engine warm(egr open)feel for
miss when shifting into od. No code will be set.

That's all I can think of right now
good luck!