Hi all,

I have an 01 Screw, 5.4 4x4, 145k miles. I bought it new in 01 and maintain it myself.
Water/condensation in a random spark plug well is unavoidable as we all know, however, I have not had to replace any of mine. I would simply dry the well, plug, boot, connecting spring, etc.
I installed a blue tooth ODB2 interface and use the "Torque" app to monitor real-time misfire information, specifically, I set up alarms that trigger after so many misfires. Only in extreme cases would I get the check engine light.
I also learned to listen and feel for any hesitation at idle, even the smallest hiccup could be heard in the intake tube and felt via floor board.
I recently decided to replace the OEM originals for good measure. I read all the reviews on all of the different Chinese cheapo's but went with them anyways. I installed them at 135k miles.
The cheap COPs have worked fine until a recent misfire condition. When I pulled them out I discovered that the top weather seal "lip" on the rubber boot was damaged on all 8. I guess when I inserted them into the plug well I may have went too far or, they got hot and brittle and broke. Regardless, after comparing them side by side, the factory OEM motorcraft boot is much more robust. I also noticed that the high voltage "spring" was not as tight where it connects to the post on the coil, I could spin it very easily as compared to the motocraft, which I could not spin at all.
Rather than swap the rubber boots with the original motorcraft, I opted to toss the Chinese stuff and ordered the Denso COPs from Rock Auto. I will post back with my experiences.

 

Been running 8 Denso COPs for about a month now in my 01 Screw 5.4. So far, so good. They appear to be comparable to the originals in fit, quality, and function. If they stand the test of time, they're a steal at less than half the price of the Motorcraft (from Rock Auto). We'll see.

 

You can buy just boots/springs
They are dirt cheap

Carbon tracks in boots mor split.can cause misfires

 

I know quite a few running them now, all good so far which is great. It would be nice having a cheaper alternative to Motorcraft. Denso's are new, I don't know how they're building them yet. So far and if they remain solid, you have to think they are giving them the same build magnet design and thermal protection as the Motorcraft builds. Hope so!

 

I installed new plugs and Denso COPs today. I use the torque app on my phone to monitor real-time misfire counts via a blue tooth ODB2 module. The Densos appear to have high quality boots and the coil unit seems to be quality construction, slightly different than my OEM motocrafts and the cheap chinese knock-offs that I had. I will report baxk with any issues that pop up with the Densos.

 

This^^^^ don't buy coils until you try this first. It can save you lots of money and OEM coils rarely go bad.

 

Huh I might get a set and motorcraft plugs soon. Would you buy em brew?

 

At this point I would. User Jethat was one of first to try them. He's had them for awhile now. There's others as well. Not one bad experience yet.

 

Badfish--being a frugal person, I did try changing the boots and springs first as mbb wisely suggested. Unfortunately, two of the original coils were still misfiring sporadically after getting good and hot, so I figured I'd bite the bullet and replace the entire lot of them. Checking just now, I have 2700 miles on them so far without a hiccup.

FWIW, Denso, the name, is new. But the company is almost 70 years old. Formerly called Nippondenso, Denso is partially owned by Toyota, and has been making electrical components for cars since WWII. In addition to all the starters, alternators, and switches, they produce all the spark plugs and COPs that Toyota/Lexus uses on their production lines and then some. According to Wikipedia, they are the fourth largest auto parts producer in the world, and they have earned a solid reputation for the quality and durability of their parts. That being so, I figured that I'd try them. The price was certainly more favorable than what the folks in Dearborn were askin' for theirs.

Let us know how you fare gkoenig.

 

That's the way to do it!