Spark Plugs?

[nvycrmn]

I know there are a lot of threads out there for spark plugs, but I still have a question. When driving (while RPM's are low, 1500'ish) the truck feels like it is missing but there is no code. When I begin to climb a hill or whatever, the truck seems to miss as well until it downshifts, then you dont feel it as bad. I am suspecting spark plugs, as they are well overdue! (117k on it. i have had it for over 30k so not sure when plugs were last changed). truck seems to run at 1400'ish rpm at 45 mph. low rpm's is when it is noticed the most. i need to make sure the truck is ready for the 1800 mile trip back to iowa in 28 days!

 

[Ron1978]

Ours done this

We took it to shop and they found a coil PAC miss firing on cyc 1
Replaced it and it fine now, truck never gave a code either

 

[treycool94]

my mom says it doesent have spark plugs can i get a strait answer on this

 

[jacks3am]

yes all expys have spark plugs and all 5.4 engines have coil packs, some 4.6's have plug wires, I would say replace everything as in plugs and cops just to make it run in tip top shape

 

[treycool94]

so i have spark plugs and coil packs?

 

[toms89]

so i have spark plugs and coil packs?

Yes.. all gasoline motors have sparkplugs. Diesels do not

 

[Thermo]

nvycrmn, take a look at the top of each of your COPs and see if you find any with cracks in them (will look like a white line, normally running around the edge where the clear/white top meets the black plastic edge). if you see a line, replace that COP. Odds are, you will most likely find it on cylinders 3, 4, and/or 7.

Do you notice the missing more right after it has rained or you have driven through a puddle? If so, this also confirms you have a COP with a crack in it.

The other thing that I would tell you to do (and I know you are not going to like this) is to pull out each of the COPs and take a look at the rubber boot on the COP. There have been instances where the rubber has degraded over time and has started to short through the rubber boot, allowing the spark to bypass the cylinder (spark jumps from the coiled wire between the COP and the plug, through the rubber boot, to the plug well wall. You can spot this if it is occurring because the rubber will become very brittle and may even see a little bit of burning of the rubber boot.

 

[nvycrmn]

there really has been no rain here in SD so...no. hahha. It has been running like this for about a month or two now, at least that i have noticed. i attempted (with Panda) to change the plugs on it a few weekends ago, but that damn back passenger side (i believe #4) pissed me off so much that i said screw it. but i dont have 300 bucks to have somebody replace them for me, especially since i have new plugs waiting to get installed! i will have to check the COP's, and maybe it is just time to replace it all. i dont mind the front six, i just dont have the patience for the back 2!

my other concern is this "blowing plug" syndrome that we all hear about. i cannot afford to blow a plug in the mountains of CO on my way home!!!! how often does this occur in our engines (1st gen 5.4).

 

[panda24619]

yeah you werent in the best of moods that weekend. not a good day to be around you with a wrench. haha

 

[Nas1]

Had the same issue with mines. I replaced all the plugs and it was or is still miss firing. Looking into getting coils from ebay now. And yes it took me 5 hours and alot of cussing to get to the last rear most 2.