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-   -   spark plugs (http://www.wranglerforum.com/f282/spark-plugs-40497.html)

ski0rb0ard 11-28-2009 08:41 PM

spark plugs
 
so i was reading in the service manual that the jeep needs new spark plugs at 30,000 miles and i am right about at that mark. what do you guys think? is it just a way for them to get more money? or is it legit?

terrible2 11-28-2009 08:57 PM

I believe the stock Spark plugs run NGK..., I took mine out at 30k and my friend said that there was alot of life left in them so yea you probably dont need to take them out at 30k but heck theyre only $7 a piece x 6. When you change them out make sure to do it yourself youll save ~$200 and get Autolite APP985, double tipped platinum, not since Ap985 as you will have some misfires and not get as great output as the APP985 would. They last 100k miles.

Jerry Bransford 11-28-2009 10:35 PM

If you're still running conventional plugs, like the factory installs, odds are they are close to needing replacement. What year TJ do you have? Is it old enough to have a distributor or is it a newer distributorless engine?

terrible2 11-28-2009 10:54 PM

whoops forgot it was only certain post years which needed double tipped platinum

daanbc 11-29-2009 10:22 AM

Speaking of plugs, I bought my 2000 sahara back in march from the original owner (female) When I purchased it her dad was there, he was the one who took care of it, washed/waxed/maint. It had 117k. Now it has 122k, I have had NO problems with it at all! She runs real smooth at all speeds. But I never pulled any of the plugs to look at them. Do ya think I should replace even though she runs great? How difficult is it to get to them? I've looked and all I see is that fuel/coil rail? What plugs should I get for the future also? I want to do it right the first time. Don't want to get a plug that runs to cold. Thanks.

coolbreeze 11-29-2009 10:41 AM

I bought OE plugs from the dealer. Not expensive and he had them in stock. Check your manual for recommended radiator flush interval also.

Jerry Bransford 11-29-2009 11:52 AM

Quote:

Originally Posted by daanbc (Post 496361)
Speaking of plugs, I bought my 2000 sahara back in march from the original owner (female) When I purchased it her dad was there, he was the one who took care of it, washed/waxed/maint. It had 117k. Now it has 122k, I have had NO problems with it at all! She runs real smooth at all speeds. But I never pulled any of the plugs to look at them. Do ya think I should replace even though she runs great? How difficult is it to get to them? I've looked and all I see is that fuel/coil rail? What plugs should I get for the future also? I want to do it right the first time. Don't want to get a plug that runs to cold. Thanks.

Since yours does not have a distributor, two very good plugs that will last approx. 100K miles are the Champion 7034 and the Autolite APP985. Both of those are double-tipped platinum plugs which is what your engine requires if you want to run a long-lasting platinum plug.

Your newer distributorless engine is fussy about the type of platinum plug it gets so make sure to avoid any single-tipped platinum plugs like the Autolite AP985 like I use in my older 4.0L that has a distributor. Single-tipped means the platinum is on just one side of the gap, double-tipped means the platinum coating is on both sides of the gap.

If platinum doesn't ring your bell like it does for me, it is not as fussy about non-platinum conventional plugs. I would just avoid installing any of the gimmick plugs like Splitfire or the Bosch Plus2 or Plus4 which for some reason don't often run well for long in the 4.0L engine.

daanbc 11-29-2009 12:27 PM

Quote:

Originally Posted by Jerry Bransford (Post 496392)
Since yours does not have a distributor, two very good plugs that will last approx. 100K miles are the Champion 7034 and the Autolite APP985. Both of those are double-tipped platinum plugs which is what your engine requires if you want to run a long-lasting platinum plug.

Your newer distributorless engine is fussy about the type of platinum plug it gets so make sure to avoid any single-tipped platinum plugs like the Autolite AP985 like I use in my older 4.0L that has a distributor. Single-tipped means the platinum is on just one side of the gap, double-tipped means the platinum coating is on both sides of the gap.

If platinum doesn't ring your bell like it does for me, it is not as fussy about non-platinum conventional plugs. I would just avoid installing any of the gimmick plugs like Splitfire or the Bosch Plus2 or Plus4 which for some reason don't often run well for long in the 4.0L engine.

Thank you very much. I will write those two plug #'s down in my haynes book. This way in the near future I won't need to bug anyone anymore about this subject.:D

Hensman 11-29-2009 01:16 PM

[QUOTE=Jerry Bransford;496392]

Your newer distributorless engine is fussy about the type of platinum plug it gets so make sure to avoid any single-tipped platinum plugs like the Autolite AP985 like I use in my older 4.0L that has a distributor. Single-tipped means the platinum is on just one side of the gap, double-tipped means the platinum coating is on both sides of the gap.

QUOTE]

So are double platinum plugs are better for the distributorless engines?

terrible2 11-29-2009 01:58 PM

Yes

ski0rb0ard 11-30-2009 01:26 PM

i have a 2005

do i have a distributor? because i dont know

and what would the best plugs for me be then?

Jerry Bransford 11-30-2009 02:33 PM

Quote:

Originally Posted by ski0rb0ard (Post 496875)
i have a 2005

do i have a distributor? because i dont know

and what would the best plugs for me be then?

No, your TJ has the newer distributorless ignition system that is more reliable. For your TJ, I'd run either the Champion 7034 or Autolite APP985 (not AP985!) spark plugs. The newer distributorless ignition system like you have is fussy about its spark plugs, it won't run well on just any spark plug like the older 4.0L engines would... mostly. :)

coolbreeze 11-30-2009 02:40 PM

Quote:

Originally Posted by ski0rb0ard (Post 496875)
i have a 2005

do i have a distributor? because i dont know

and what would the best plugs for me be then?

No, you don't have a distributor. On the underside of your hood, there might be a white sticker that says (Vehicle Emission Control Information) it will list the OE plugs. My 04 came with NGK RZFR5N, and they work just fine.

DKarge87 12-02-2009 06:50 PM

I installed a set of e3's and they are nice! I installed those and a k&n drop in filter and noticed a differance in drivability and mileage and you cant beat the test results that are backed up

Jerry Bransford 12-02-2009 10:22 PM

The K&N contributed nothing to the difference you noted. That is because the paper filter that used to be in there was more than capable of providing all of the air the 4.0L is capable of consuming at redline and wide-open throttle. The TJ's air intake system, unlike many other vehicles, is not restrictive... not in the least. Many other air intakes are, like on the Mustang 5.0L engine, but the TJ's is not. It was purposely designed to be non-restrictive. :)

Rawkon 12-02-2009 11:46 PM

ive been running the champion copper truck plug. i believe the same part numbr jerry posted. my little jeep run great.

adkjoe 12-03-2009 07:32 AM

So what's recommended for the 2.4L engine. It's distributorless also. The same Autolite APP985?

Jerry Bransford 12-03-2009 10:39 AM

Quote:

Originally Posted by adkjoe (Post 498544)
So what's recommended for the 2.4L engine. It's distributorless also. The same Autolite APP985?

Someone else will have to answer that question as I'm not familiar with that engine. But do you know if your 2.4L has a coil for each of the four spark plugs or does it share a coil between two cylinders like the newer 4.0L engine does? In other words, does the 2.4L have two or four ignition coils?

adkjoe 12-04-2009 08:22 AM

What are you 2.4L guys running for plugs? I out in the Bosch double tip platinum that's all they had in stock. No misfires but I don't think the jeep likes them.

Jerry Bransford 12-04-2009 11:51 AM

Quote:

Originally Posted by adkjoe (Post 499204)
What are you 2.4L guys running for plugs? I out in the Bosch double tip platinum that's all they had in stock. No misfires but I don't think the jeep likes them.

Bosch makes a good quality plug but for some reason, I don't think they make a plug that any of our Jeep engines like. I read an explanation for that year ago written by a Bosch engineer and I think it had something to do with the heat range but I don't recall exactly. I've tried to find it again before but couldn't, I wish I had saved it.


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