Cranked up my F150 yesterday and all the sudden it was "missing". It's a 4.6L (04'). I found out that #8 cylinder miss firing. But what part is bad! I have a feeling it's a coil on plug that is bad. Motorcraft parts are recommended...$60.99 at Advanced Auto. There is a lot of others to choose from for half that price I see but I want what's best. I saw a U Tube video of someone using DENSO coils....But!! Looks like I have to find a mechanic to do this job. #8 cylinder is on the drivers side against the firewall and that looks like a tough job. Always something. Any comments on coils?

The autostores can run scanner to make sure it is the coil. I have had them of the 06 Merc I have, not hard as I remember, some of the plug boots are tough to get off. Denso are good products. Only thing different about the coil with Motorcraft on it is the price. bg

[quote=Shadetree]The autostores can run scanner to make sure it is the coil. I have had them of the 06 Merc I have, not hard as I remember, some of the plug boots are tough to get off. Denso are good products. Only thing different about the coil with Motorcraft on it is the price. bg[/quote

I took the trk around the corner to an Inspection Station, they work on vehicles there also, and the tech put a scanner on it but only showed that #8 was misfiring and not what was actually bad. Closest auto store here is O'reillys in Santa Fe.

Whats your mileage? When I have a missfire on one, I always replace that coil and spark plug together! If its over 100k, then I would recommend all spark plugs and coil boots!

I agree but it's not in the budget right now.. 122,000 and never had a problem until now.

Go on www.f150online.com, Lots of guys there to help out. Next what year is your 4.6L? I have had a 97 and an 06 F150's with the 5.4L and at one time they used the same Coil On Plug set up as the 4.6L and I bought replacements on ebay that had a life time warranty full set of 8 for less than $100 only had one go bad and they sent a replacement. Lots of things to consider as the modular engines were temperamental. First off stay with the Motorcraft Plug when you do replace plugs and or COP's make sure you coat the inside of the boots with dielectric grease. Secondly follow the replacement proceedure to a T Believe me. You are going to here all kinds of [censored] from some people about how terrible these models were, well just consider the source. I put 200K plus on my 97 and 170K on the 06 and never launced a plug on the 97 and only had two plugs break on the 06 from first tune up and other that the one bad coil no other problems as long as you know "how" to work on them.

As stated in original post.....it's an 04'

Do you know if your 04 uses the DG-508 or DG-511? This is an example of replacements for the DG-508's

https://www.ebay.com/itm/New-Delphi-GN10164-Ignition-Coil-Set-of-8-For-Ford-Lincoln-Mercury-DG508/173650232930?epid=93738202&hash=item286e5c4662:g:dQ8AAOSwdrpb8xf1:rk:3:pf:0

or if you must have OEM then these

https://www.ebay.com/itm/Set-of-8-OEM-DG-508-Motorcraft-Ignition-Coil-Ford-Lincoln-Mercury-4-6L-5-4L-6-8L/192008631603?epid=79015647&hash=item2cb49b3533:g:cV0AAOSwbiFZOe6H:sc:USPSPriority!75482!US!-1:rk:4:pf:0

I am almost positive its the 508

I run duralast coils in my �05 f-150. Just as good as factory. Motorcraft plugs are important. I like the duralast part because they�re lifetime warranty parts. When you want to change the coils, just box them up, get a refund, and get new coils. I recommend doing all plugs and coils at once. Fords tend to burn coils all at once so don�t be surprised if another one goes out soon. At 122k, you�re gonna need to change all plugs and coils soon, oftentimes you can get a bundle of 8 coils for about $200, at least that�s what I got mine for at autozone. Coils aren�t an awfully tough job, there�s really only one bolt and the wiring has to be unplugged.

I have used 3 types of coils nothing last longer than the motorcraft ones. Rock auto parts have the cheapest I could find. Motorcraft plugs only.