clw

I have an 05 with the 5.4L and about 115k miles on it. I got on the gas the other day and after about a second the truck felt like it was running noticably smoother and quieter. didnt feel a change in power. but my cel started blinking so I pulled over and read a cylinder 1 misfire. Started the truck up again after a little bit and it was gone. hasnt come back since.

Has anybody ever seen a misfire run smoothly????

and is this a sign I should change my plugs soon?

techrep

iTrader: (1)

Plugs were due @ 100K if they are original...

sargeek1975

And then change the cop on that cylinder..........

yoop

I have an 06 5.4 and it did this to me once when i got on the gas to pass three cars jsut kept going everything is fine. the CEL blinked for a few seconds but shes good to go jsut keep getting on it and if it keeps happening change the plugs. I have 83k on mine still stock plugs

clw

i'm just gonna bite the bullet and change them

JCooper

The misfire is probably from a coil pack on that cylinder.. I agree. A cylinder has to misfire hundreds of thousands of times before the cel comes on so it must have been going on for a while. My advice. Change all plugs... need to anyway. Change all coil pack boots, and replace that 1 possibly bad coil pack.

clw

theres no harm in just replacing one coil pack?

JCooper

None at all. That's usually what's done because coil packs can be expensive.

However, as I said, the boots (long rubber tube with spring inside that extends from the bottom of the coils and clips over the tops of the plugs) are cheap and should be replaced with the plugs. They can crack at the bottom from age and/or heat and allow spark to arch.

clw

ah. learn something new everyday. thanks.

techrep

iTrader: (1)

Try removing the COP and re-grease it first.