I had a MIL displayed with the codes that indicated a misfire on cylinders 2 and 6. It ran really rough too at times. Changed the plugs and the problem went away. They too looked fine. I did check the coil pack resistance and they were fine as well. All of this occured while towing the boat with around 70K miles on the odometer. My '03 model never got plugs changed the first time until 90K miles and it never missed, so... Plugs cost me $54 from the dealer and it took me about two hours to complete the job.

 

I want to see my plugs but how would I know they were really mine if I let them take the out unless I look at a few and make it look like I have been working under there they would not take the chance I have not already seen them. I just wonder why they have to be changed so often I wonder if it has something to do with not having a catch can.

 

I changed mine at 40k and they were fine. Gap was off by like .03 I think. Taking them out is kind of a pain in the ***, but it beats paying the dealership $200. There is a really good write up that explains how to do it. Use the wobble extensions and a knuckle and you'll be fine. I would recommend a 1" a 3" and a 10: extension. There are lots of things in the way and it will make it easier to be able to use the different lengths. The ones back by the firewall are the hardest to get to, but still not too terribly bad. You shouldn't have any issues. I had to buy the plugs from the dealership because I couldn't find them anywhere else. I used the OEM plugs though.

 

Can you or anyone else provide some more insight about what these coil packs you speak of are about?

Where is this write up? And I'm only somewhat mechanically inclined (hope to be more) but can you provide a link or description on what these tools are?

I am nearing the time to change out the top row of spark plugs and don't really want to pay sometime to do this but with my limited skills, I'm not quite sure I am ready/or want to tackle this project.

EDIT: I found the DIY spark plug change but it's on a 2010 5.7L. Is it the same process for a 2009 4.7L?

 

the plugs on the 4.7 are different than the 5.7. I didn't notice you had the 4.7L. I believe the 4.7 has plugs on top and on the bottom so you could be getting into more than you can handle if you've never done anything like this. I'm not too familiar with the 4.7L though so hopefully someone else can chime in here and help you out. Good luck.

 

I changed mine to Iridium's. 100,000 mile plug. There in my Corvette and Mercury Marquis also.

 

The only thing about 100,000 plugs I would be worried about is the change interval being blamed if there was ever an issue with the engine while it was under warranty. My dealership has told me that if the maintenance schedule isn't followed that's in the owners manual, they don't have to honor the warranty. So I'll be changing mine at least close to the 30,000 mile intervals. No need to spend the extra money on "better" plugs, the OEM plugs still looked fine when I changed them.

 

The 'other' 5.7s come with 100k plugs. In fact a Dodge rep mentioned such back in 2009 when I was buying. He happened to be at the dealer I bought from and I'm friends with the service manager. He commented about he'd be darned if he'd change them every 30k when they should have had a long life plug like the rest of them. Unless a tip of a plug breaks off I see no way it would affect warranty.

 

I would not have changed mine at 70K either, except the truck ran like crap! The 2003 were not changed until 90K and it was running fine. I used to hear it was because of the aluminum heads. The mechanic that changed mine it the 2003 said if it were a Ford with aluminum heads with that many miles he would not touch it as they would likely break off.

 

That was some years of the 4.6. They had shallow threads. Thousands of cars and trucks go 100k between plug changes with no issues removing them.