2.3L ('02-'11) What Spark Plugs Should I Use and Should I Replace the Spark Plug Wires?

[Arolsma]

I am planning on replacing the plugs on my 2010 2.3 with 175K miles. I don't know how old they are, but I am just going to do it. First, should I also replace the wires? Motorcraft ones are about $29 from rockauto. Also, there are nearly endless options for different plugs I could use. I want to stick with oem plugs. I heard something about the 2.3 coming with NGK plugs? Is that true? Rockauto has four different options as far as Motorcraft goes. The part numbers are SP439AX ($4.56), SP439A ($5.38), SP541A, ($6.61) and SP439 ($7.37). Should I go Motorcraft or NGK (I want whichever one is oem)? If Motorcraft, which one? Thanks

 

[Dirtman]

No ford in history has ever come with an NGK plug...

Use Motorcraft or Autolite (they are basically the same thing, Autolite makes Motorcraft plugs). Get double platinum or iridium and NOT single platinum or copper.

 

[rubydist]

And always replace the wires when you replace the plugs. I've seen many times the wires get damaged removing them from the plugs, and old wires are much more likely to carbon-track somewhere and short out.

 

[Arolsma]

So does it matter which Motorcraft plugs I go with? All four of those part numbers I listed are for double platinum plugs. One interesting thing I just noticed was that the SP541A has a .051 gap, while the three other Motorcraft plugs have a .044 gap. Thanks for your help.

 

[Dirtman]

These are the three plugs you should use for your truck.

Autolite XP-104 for iridium
Autolite APP-104 for double platinum
Motorcraft SP-541-A for double platinum (same plug as Autolite APP-104)

All gap at .051

The iridium will last slightly longer. The double platinum is O.E. No difference between the Motorcraft and Autolite in double platinum, same exact plugs both are made by Autolite anyway.

I personally use the Autolite XP-104 iridiums in my 2009 2.3.

 

[Arolsma]

Thank you very much for your help. I think I will go with the Autolite APP-104.

 

[Garth Libre]

The Autolite Iridiums are not expensive. I believe they are the better plug and as long as a person is going through the trouble of replacing the plugs and the wires, why not spend an extra ten bucks? I suppose the Iridiums don't actually improve performance but only last longer, but they only cost a little more. I would also go through a little extra trouble and expense of using a swipe of dielectric on the spark plug and boot release on the boot. The 2010 4 cylinder is apparently a lot easier to replace plugs on than the earlier 4 cylinder which takes 8 plugs, so consider yourself lucky.

 

[89Twincharge]

I've always used copper plugs over irid/platinum and never had a problem... even though autolite makes motorcraft motor craft are made with better materials.... I use to work at a battery plant, we made Optima as well as other brands but we had different mixtures of lead for each one...

 

[Dirtman]

Copper plugs will work fine as far as performance but they were never designed for a modern EDIS waste spark ignition system so they will last only a fraction as long as a double platinum or iridium. If you have an older distributor style ignition then it doesn't matter but EDIS in general has more voltage running through it, and with waste spark the plugs are firing twice as much. So it's basic math, if your copper plugs lasted 100,000 in a distributor ignition, they are gonna last 50k in a waste spark EDIS. All depends how often you wanna change plugs...

 

[89Twincharge]

Iridium plugs melt.... all 4 plugs were melted, number 4 cylinder gave out first and impacted this one... this is a k24a4 I had in my shop today. customer said they needed a starter, they need a motor. So I'll stick with my coppers! Lol

 

[89Twincharge]

If janitor doesnt take my bin out tonight I can get a pic of other 3.. cars may be designed to use certain plugs BUT that's for emission and mpg ratings not longevity. Also why so many parts are made of plastic... light weight, cheap, and require less skilled workers to make... I've changed more cracked plastic water housings on bmw, vw, mercedes and modern domestics then I ever have an old steel one for rusting out. Except chevy 350 water outlets they always seem to warp!

 

[Dirtman]

Well that certainly is... words...

 

[grcmptrnrd]

No ford in history has ever come with an NGK plug...

I beg to differ. My 2009 2.3 Manual, purchased new, had NGKs from the factory until today. Yes, this was a surprise to me when I read it somewhere years ago and confirmed at the 90,000 mile inspection.

Changed out with 247,xxx miles on plugs. Plugs were rotated at 90,000 miles to even out wear between the "forward" and "backward" firing plugs in the waste spark system. At 90,000 the plugs were still about .052 gap, NGKs spec for the new plugs so they went back in.

No noticeable difference in performance after changing, but I assume these contributed to the failure of ignition coil #2 (aftermarket). Original coil failed due to a crack in housing.

Pictured is the plug from Cylinder 1 with the worst wear of all the plugs. Seems to be about 2x a .044 wire gauge. Platinum puck on ground electrode is totally gone on this plug. Note the NGK part number and Japan on the shell, but no other branding.