Truck is a 2004 F150 with a 5.4L 3V engine with 18,400 miles. After warms up it idles terrible ie can be felt in the vehicle through the steering wheel,seats, center console etc. Taken it in twice for this problem and have been told that the idle is characteristic of these 3V engines, some worse than others. Does this appear to be characteristic of these engines? I love the truck but I'm starting to consider a trade. I would appreciate any help with this idle problem. The truck goes down the road with no problem.

 

the 5.4L has always had a rough idle characteristic..

 

If your truck is a Supercab or Supercrew 4x2, depending on when it was built there's a TSB for updated motor mounts, neutralizing the exhaust and reprogramming the PCM for an idle vibration. My Supercab does this, just haven't gotten around to fixing it yet.

 

Just want to add my 2 cents - I have an '05 Screw with the 5.4 3V engine. Using regular motor oil (ie. Motorcraft 5W-20), the engine always had a rough idle, sometimes a bit too rough for my liking. I switched over to a synthetic motor oil (5W-20) and it's been alot better. Every now and then, the engine does have a rough idle but it's considerable more dampened than using dino oil.

 

The Motorcraft oil is a synthetic blend. I think the change is in your head more than in the truck itself. JMHO.

 

DBF: Find another dealer I have the same exact truck 5.4 3v 4x4 SC with 18,800 mi. and it idles as smoothe as silk I am using MC 5w20 syn. blend whick I don't beleive would make a bit of difference, the only thing mine is bone stock have not messed with one thing, there is no reason for these engines to idle rough!!