Rough idle on there 5.4 engines?Service call again today said oil change help it a little ,the coil stress checked out ok and the injector flow test checked out ok.Now they are telling me that its normal varible timing thats causing the rough idle.Does that make sence to anybody?Thanks for any information you can give.BTW this is on a 05 screw.

 

Mine is smooth as silk.

 

When my truck has set for a couple of days it has a little bit of a rough idle at first, but then its smooth after that. But that is my opinion of smooth over a true dual exhaust.

 

Ditto, with 30K on it. Question, does the 5.4 come with 2v and a 3v option??
Allen

 

My idle is not rough as far as RPM's go, but the engine vibrates too much for what it is, at idle in D you can feel a slight vibration in the floor/seats/arm rests etc. I took it in and the Service Manager road with me and admitted he could feel the vibration in his seat but thought it was normal(go figure). They replaced an exhaust dampner and unbolted and rebolted everything back up. That helped some, but in D I can still feel a very slighty rythmic vibration, and can see it slightly in the passenger seat when not occupied. Oh well.

 

My idle is ultra smooth since I changed plugs

 

Depending on when your truck was built, there's a TSB for 2WD 5.4 3V Supercabs and Supercrews for idle vibrations, involves replacing the motor mounts, "neutralizing" the exhaust and reprogramming the PCM. Mine has a pretty noticable idle vibration, I just ain't worrying about it right now.

 

Idle condition on my 04 SCrew with 13,000 is rough. Been back to the dealer several times, at first they said it was definitely rough and was not normal; applied TSB's, reflashed the PCM, etc. Idle condition never improved so now it is "normal for a V8 pickup" and they can do no more about it.
Mine does the same as silverbullet5.4 but is a lot more noticeable; a rhythmic vibration that runs through the whole vehicle.

 

My idle was rough too before I changed plugs and after seeing the plugs it was no wonder ~ I think they leaked compression a little

bad plugs

 

From '04 and on, the 5.4's have 3 valves per cylinder. Prior to '04 the 5.4's had 2 valves per cylinder. The 4.6's are 2 valves per cylinder no matter what year.

Dave

 

Yes, I to have the dreaded rough idle. Mine is noticibly bad in the heat or with the AC off. As Quintin noted above, there is a TSB out on this, I got my truck into the dealer as soon as the TSB hit. My truck has been reflashed 4 times for various issues, the rough idle never did get any better. I'll post back as the parts were not in stock Friday so I should get my truck back Monday afternoon...If that doesn't help, I'm going to try plugs...

 

I have 04 5.4 3V with 16,000 and never a bit of trouble. Smooth all time whether cold or not.

 

No.

 

Ditto

 

I have it. Its not real bad, but I notice it. When in D and I have my foot on the brake, I can feel it and see my passenger seat vibrate. If I let off the brales, it goes away, or if im on the brake and give it just a little gas, it smooths right out. I'll let the Ford Engineer figure it out, if and when he ever comes to look at my truck.


BREW