I have a 2006 F150 FX4 and it only has 6000 miles on it. I had to replace the torque converter already around 2000 or 3000 miles. Now the truck feels like it studders in between 45 and 60 mph. Also when it idles it is idling rough, almost like it is studdering when it is idleing. I was trying to get some feedback on what it might be. I have run fuel system cleaners through it and that doesn't seem to help much. I am not sure if it is a transmission problem or not. The mechanic says that it is my spark plugs but I have had them replaced as well. (On a side note is there an aftermarket spark plug for the 2006 f150's, because I don't like the stock ones, they say that they run cooler but they are more hassel than anything).

 

You may have to replace one or more of the coils. I have replaced two already.

 

How do you know that a coil needs to be replaced?

 

I had all my coils and plugs replaced at about 45k. I noticed it only while under heavy acceleration...my engine felt as if it were skipping and I could easily hear the misses through my exhaust. Ford can detect this via the computer reading...I think they may run it on the dyno to simulate the stress.

If you are not technically inclined or have the tools on hand to replace these parts, Ford isn't too expensive to replace them...but if you have an afternoon to spend under the hood, you could save yourself a good lump of change.

 

The bad part is I have already had some coils replaced once. This is the second time to have this happen. I guess the only thing I can do it keep having them fix but it is really tickin me off!!