I have a 2006 5.4. And I have the rough idle too. After countless hours of reading, I have come to the same conclusion that others are saying. It's normal for these trucks to have a rough idle. I probably feel it more because I'm paying attention to it when I drive, I don't think my passengers can even feel it, but I know its there. I also read that changing the transmission fluid would make a difference. And so I've done that during one of my fluid changes, and I must say that YES, it did make a difference. BUT only for a little while. After about 5,000 miles after the fluid change, the rough idle was back. Nothing bad...I hope haha.

 

Bringing this back to the top. Has anyone found a solution to the rough idle in the 2006 4.6? The reason I am asking is that I just picked up a 2006 4.6 with 6,781 miles on it and it has a rough idle but only after it has warmed up. I wouldn't say it is really bad but to me it is Definitely noticeable, sometimes worse than others. Mine is just out of warranty but I talked to Ford warranty deaprtment and most of the electronics on the emissions is covered until 80,000 miles. I may just take an infrared gun and check right at the header for each cylinder and see if one is much lower than the others. This would help if its a leaky injector or ignition problem for that cylinder but wont help if its a vaccum or IAC issue. Any others that have discovered this problem?

 

I had a 2004 reg cab 4x4 4.6 v8 xl,bought it new,and it always had the vibration/tremble. Now i have a 2006 4.6 2wd xl with about 67,000 miles on it, and it has the same vibration/tremble. it drives fine otherwise.

 

Do you notice it when the motor is stone cold? I'm thinking theat when the motor goes into closed loop after it warms up that the problem becomes noticeable

 

i think it's the same cold or hot.i noticed that if it is in drive,and on a slight uphill grade,like waiting for a red light,it smoothes out.

 

i also have a 2006 with the 4.6 andyes it has the same rough idle yall are refering to. i have also had mine checked out with no cures. i thought mine was the only one until i seen this thread. i'm gonna look a lil further into this myself. i'll keep posted if i find any fixes.

 

I had rough Idle and would get a cylinder 3 misfire. Tried new spark plugs, fuel filter, injector cleaner, injector and moving coil packs around. Nothing worked so took it to the ford dealership. They founf that the wire to the coil and injector was bad put new wires and cleaned the injectors. Cost me $500 run's like new.




2001 Ford F-150 Suppercrew 105k 5.4L V8

 

Im in the same boat just bought a 08 with 39,000 has a rough idle as well.I bought something newer to avoid problems...let the guessing games begin again.

 

I love the truck otherwise it's awesome!

 

It's normal. Took my 06 4.6 for Same thing. My friend done same thing

 

04 150 with a 4.6 and 182000 but never had the rough idle issue

 

Gotta love normal abnormalities! Hahaha!

 

06 4.6 51,000 miles no issues with rough idle,,feeuuff

 

My truck was doing this a few weeks ago. It was also the same time that I had filled up at a "questionable" station. It hasn't done it since I filled up at the usual Texaco. Could be bad gas.

 

I own a 2007 f150 4.6 also have a slight rough idle.
ford wants to sell me a tuneup plus an injector cleaning.
just under 100k on the engine.. this idle thing seems to be a trait of the 4.6
argh..:think