My 2003 Ex has logged a few misfires...I've even felt it skip at times. It has 255k on it and the PO evidently couldn't even spell maintenance let alone do any. Point being that it may have the factory plugs still in it. I didn't change plugs in my Dodge Caravan until about 210k and it was still running fine. But I've been driving it and working on it as time allows. Yesterday, when I left work. it was noticeably skipping. It was snowing although I can't see how that would have anything to do with it...I've driven it in the rain with no issues. Anyway, it was missing badly enough that I took it out of OD because it was shaking the whole truck. By the time I got home, it was chugging like a Harley with a fouled plug. Someone on here told me, on another thread, that an intermittent misfire was likely a bad boot? And, if I understood correctly, a coil pack was much less likely to produce an intermittent misfire? My Livewire didn't pull any codes and I haven't had a chance to plug in my scanner to check for temp codes yet. So this morning, since there was a couple of inches of snow...that qualifies as a major school closing roll up the sidewalks because you're probably gonna die event in North Ga...I drove it to work again. Smooth as silk. Never felt it skip. I have new plugs and boots that will be installed on some magic day when time and motivation are both present. I've thought about coil packs, coil pack wiring, and injector wiring but are those likely to cause it to run badly one day and fine the next? Just fishing for ideas from those who have already dealt with this before I start taking things apart.

 

Get some new boots/plugs in it ASAP.

I've found that the V10 tritons don't throw codes too easily with intermittent misfires.

A bad coil pack/boot would certainly cause an issue you've been having.

My old Expedition would start having misfires on damp days when moisture/dew point was high. Traced it down to tiny little cracks on top of the coils themselves, plugs and boots were fresh, figured it out by opening the hood at night and watching the coils arc to the engine, so just food for thought.

 

I need to try that tonight...should have thought of it. I'm surprised someone didn't come up with a retrofit that solved the coil issues. I never remember having a bad coil on older vehicles.

 

Lol, there really isn't a "coil issue" with this design, you have a quarter million miles on yours and they still work fine most days!
Older vehicles typically only had the one big coil, if that went out you were walking, with the Coil On Plug design you can have one (or more) coils go bad and still be able to drive (with a miss).
Old boots tend to develop very tiny cracks that can bleed voltage out to the spark plug well, which causes a miss. Rain, snow or any other higher humidity condition will increase the odds of this happening. An old boot can still look pretty good but these tiny cracks will be there.

 

I have an 2000 x with 225000 miles on it. High humidity will cause misfire. Coil wire is the issue with mine. 100.00 for the wire plus labor. Have had 4 wires replaced so far. Will need another soon. Misfires going uphill now and will get much worse on a high humidity day.

 

As Tom mentioned, there are not any specific failure points with the Coil on Plug system in the modular Ford engines per se. Time/age/heat cycles take their toll on stuff under the hood.In regards to my issue, I guess I should have also included that the arcing issues I was having were due to age and about 100k miles, not to mention that a buddy of mine did me a "favor" by pressure washing my motor a couple of months prior to the fact.

 

I'm going to try just replacing the plugs and boots. I did look under the hood this morning when I started it and did not see any arcing. Ran smooth all the way to work. I thought about taking a spray bottle...like on a day it's not 10 degrees out...and misting the tops of the coils to see if that caused arcing.

As to the coil issues, I've owned many different spark ignition engines over the years and a couple of outboards are the only ones I remember ever actually having a coil failure on. This is the first one I've ever owned that uses COP. There seems to be quite a bit of discussion about these Triton engines misfiring. I hadn't paid a whole lot of attention to it until I drove my 5 cylinder Excursion home the other day. I expect the "issue" in general has been exacerbated by people buying the really cheap replacements and experiencing rapid failures.

I've read that the Denso coils are good quality as Denso makes them for Motorcraft. I wonder about the "lifetime warranty" Autozone Duralast coils? They're around the same cost as the Denso units. I've had pretty good luck with Autozone parts in general.

 

Ok I'm cranky this morning.

Why spend time and money flopping around trying to half a$$ an issue?

Just buy 10 denso COPS and 10 new spark plugs and be done with it!

Put some orings on cops to prevent water intrusion too.

Check cop and injector clips for any being broken....or better yet spend $30 for new ones.

It' got 200,000 plus miles on it for $$£&!&# sake.

 

Thanks for that well thought out reply. I've never considered not replacing functioning parts as half a$$ing nor diagnosing the actual issue as "flopping around" but perhaps I'm just being unreasonable. Yes, it has 250k on it but I don't know if these are the original coils are not...I only know that the last owner wasn't very in tune with doing maintenance. 10 new Denso COPs are going to run me close to $500.00 based on the prices I've seen and that's an expensive insurance policy. $30 for new cop/injector clips sounds like a good idea...are those available aftermarket or are they dealer only?

 

https://www.ebay.com/p/Direct-Ignition-Coil-Coil-on-Plug-DENSO-673-6000/112900115?iid=351970565762&rt=nc

10 new Denso cop for $269 ish

subtract the $80 you would spend on new boots and it's just $190 more than you originally estimated.

injector clips
https://m.ebay.com/itm/8PC-EV6-EV14-USCAR-FUEL-INJECTOR-PIGTAIL-CONNECTORS-FORD-CHEVY-DODGE-FAST-LS2-3/151274331854?hash=item2338a71ece:g:lSYAAOxyUylTRAm Y

 

Thanks for the link. I was just on Ebay last night and searched for "Denso Ford V-10 coils". I did not find them for that price...def a good deal.