4.0L Spark Plug Dilemma - JeepForum.com
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post #1 of 8 Old 07-27-2009, 05:42 PM Thread Starter
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4.0L Spark Plug Dilemma

After reading the forums, I purchased AutoLite 985s. I was going to gap them and do the install along with a bunch of other things, but I'm moving (tools packed) and so I had my mechanic do it.

I brought him the plugs and other things only to find out that he did not install the 985s saying that they werent the right ones and that Jeep 4.0s dont really use AutoLites.

Instead, he installed Champion Platinums (not sure of the number yet). I have the AutoLites still.

Are the Champions okay? What's the diff between the AutoLites?

The Jeep runs fine as far as I know.

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post #2 of 8 Old 07-27-2009, 06:15 PM
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Copper Champions win the most used contest fir the 4.0.
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post #3 of 8 Old 07-27-2009, 07:43 PM Thread Starter
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Originally Posted by 98junk View Post
Copper Champions win the most used contest fir the 4.0.
Is there any advantage to the platinums or just wasted money?
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post #4 of 8 Old 07-27-2009, 08:04 PM
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wasted money. The only plugs I will ever run in my 4.0 are the plain-jane copper core Champions or the Champion Truck Plugs.
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post #5 of 8 Old 07-28-2009, 09:50 AM
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Spark plugs can be a tricky issue.With a jeep I feel you should only use what the O.E.M recommends. Which is a plane jane copper core plug. Don't fall into that trap of 4 prongs and made out of materials from the moon mumbo jumbo. The truth is that electricity takes the path of least resistance and only will use one prong anyway, and most vehicles will not bebefit from a sophisticated super duper 10 dollar nutronium plug or whatever they got nowadays anyway especially a jeep. Save your money and get a stock plug you will be thankful in the end.
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post #6 of 8 Old 08-12-2009, 02:55 PM
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Champion 4412 vs 3412

I purchased a set of Champion 4412 Truck Plugs for my 4.0L and they sent me Champion 3412 Platinum Power plugs. They checked with Champion and said that the 3412's are a direct replacement for the 4412's as Champion does not make the 4412's any more. Has anyone tried the 3412's yet?
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post #7 of 8 Old 08-12-2009, 07:36 PM
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There is only one benefit of a multi-prong plug... forced induction. When you increase the pressure and speed of the intake charge it can have a tendency to blow out the spark of a single prong plug... having multiple prongs allows a secondary spark to complete the ignition should the spark blow out w/o closing up the gap so much that you lose the size of the spark. It did wonders for all my forced induction engines, and really bit the big one on my nitrous engines. With NA engines, especially a stock Jeep 4.0L... follow the rules of the Jeep itself, keep it simple. Theses things are already like Lego's... you just pull something off and swap something back on. Do yourself a favor and keep it simple and rarely will that ever steer you wrong.
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post #8 of 8 Old 08-12-2009, 08:14 PM
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I called Champion about the 3412 replacement for the 4412 and they said that they have discontinued the 4412 truck plug and there is not a replacement for it. I went to my local Advanced Auto parts store and they had 12 Champion 4412 truck plugs. I bought all twelve! When I cannot find the Champions anymore I will just go with the OEM plugs, NGK-ZFR5N/3459 as stated on the emmissions sticker under my hood.
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