My trucks a 2006 FX4, i got ~70k klms on the clock. I changed the spark plugs out in the fall. Recently ive been doing some city driving and while accelerating in 3rd gear it will get to about 2000rpm and have a shudder and fall down to 1800 rpm then keep going till it shifts into 4th. what could be causing this? on the highway or under heavy or really light acceleration it works fine but in traffic it seems to get me just about every time. Any ideas or solutions? Thanks!!

 

What engine ? Do you have a MIL or CEL on ? Sounds like a coil. Did you get the engine wet recently ?

 

its the 5.4L 3V. Its been raining a lot lately but it does it when its dry as well. I was thinking a coil as well. Are they hard to replace? No CEL or any light on.

 

go to e-bay and search dg511. you can get a whole set of coils for about $100. I'd have the dealer install them while doing a plug change unless your an ace wrench who can follow the TSB to a T and you have the tool for extracting broken plugs in that case do it all yourself.

 

the plugs were recently changed, no more than 5000k on them. Do i need to change the plugs to do the coils? looks fairly straight forward...

 

no. If that one is bad then youll have to do it. I would just feel comfortable pullin that plug if nessesary. Cant be to much carbon after only 5000 mile