I have a 2006 F-150 FX4 with the 5.4 V-8. Recently, when I am at a low RPM (1250), running around 45-55 mph and in Overdrive the truck will start to jerk bad when I try to accelerate with a little gas. Usually I am behind a slow driver and on a slight incline. It's like it is trying to decide whether to down shift or not. That is the best way I know how to describe it. Anyone ever experience this and can help. Feels like the transmission is going to fall out! Thanks.

 

It's probably the spark plugs. My wife's Expedition did that. Had the plugs changed and all is well.

 

Anyone recommend a particular plug or are the Ford ones good enough. I have had the 2 piece changed out already.

 

I plan on replacing mine with Motorcraft SP515. I'll buy from Rock Auto. Those are OEM replacements.

 

X2^^^^

It could be a coil pack (COP) if your plugs are fairly new. Either way, it sounds like its more of a misfire than a tranny issue. Check the codes, if they lead you to the cylinder in question then swap the cop out first...

 

If you have changed your plugs already you may want to look at the COP...sounds like a mis-fire could also be a clogged even a bad FPDM...any codes ??

 

Alright... showing my ignorance. Would the Engine light have to come on to give codes. If so, it hasn't come on. What's a COP and a FPDM....

 

Cop is a coil over plug. (Coils) and fpdm is your fuel pump driver module.

 

Roger that... thanks

 

It may take a while before it comes on, you may have a code stored already without the CEL. If you can replicate the problem purposely while driving, then you may get that code you need even quicker.