Favorite Spark Plugs For 2000 Jeep Cherokee 4.0

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I doubt you are going to be able to tell much difference whatever the brand. In my old 258 and in my 4.0 I used Champion, NGK & Autolite, all with no complaint.
 
If you can still find them:
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I don't know anybody who didn't love these in a Jeep 4.0 and if there is a group of Champion truck plug in Jeep 4.0 haters, they are few and far between.
 
Yes, Yes... I Love threads about Jeep Cherokees. Just LOVE Em! I currently have 6 XJs, four of which have the 4.0, my 87 with the AW4 auto with original everything that has 293,3?? miles, my 96 with the AX-15 5 speed that I just rebuilt and put a new clutch in front of that drives but shifts hard due to a worn out and leaking Master/Slave cylinder combo that has 248,7?? miles, my 99 2 wheel drive whose 4.0 I reBuilt(Heavily ported cylinder head, .020 milled, 6 New Sealed Power pistons, Hastings Cast rings) this summer with 140,8?? miles with the AW4 auto 2 wheel drive version(Fast Jeep), and my Beloved SilverStone Metallic 2001 with 64,6?? miles that runs and drives sooo smooth. My Favorite spark plugs are Plain Jane AutoLites(925 I believe). I have used Champion Truck plugs with good luck, my friend didnt have so good luck with those in his 88 XJ. I have used Champion Platinum, Factory Champion, AutoLite Iridium, and AutoLite Platinum plugs All with Good Luck and performance. But I am partial to the Orange box Autolite plugs, just because I believe Jeeps dont like to be pampered with to much High Zoot componentry. Your 2000 will have Coil-On-Plug, which makes it a bit more time consuming to change plugs, not to mention you can damage the coil pack if it gets smacked around or dropped, so I would recommend those Champion Truck plugs as well or AutoLite Iridiums for longer service life and less frequent change. I like to stay away from Japanese plugs for my American made Jeeps. Japanese just dosent seem right in a Bad A$$ American vehicle, though the transmissions, regardless of Auto or Manual are Japanese...Except for the 87-89 XJs with the Peugot BA10/5 5 speed, and the ULTRA rare 2000 and 2001 XJs with manual tranns that have NV3550 5 speeds...Ive only seen two of these in 6 years of searching.
 
I also believe 4.0s work best with Conventional motor oils, 10w-30 regardless of temp in low mileage, GutNtight 4.0s, and a 40 weight in Higher Mileage, worn 4.0s. My 87 has Havoline 10w-40 in its sump, my 96 has Napa 15w-40 in its sump with a Oversize Purolator 30001 oil filter, my 99 has Pennzoil 10w-30 Conventional in its sump with a Fram Tough Guard TG8 oversize oil filter, and my 01 has Quaker State 10w-40 in its sump with a Plain Jane Fram Orange PH8 Oversize oil filter. They ALL run and sound very good with the best fuel mileage going to the 87 and 99. My 87, with its 293,3?? mileage everything gets proabably the best mileage of them all, and is such a Healthy motor, oil dosent turn even dark brown until 5,000 miles or later, no burning, just a little leaking from a oil Oil pressure sending unit.
 
From my experience, iridium is the best (and most costly) choice in spark plugs. I took a set out of my daughter's Chevy Malibu after 105,000 miles, they looked NEW ! That convinced me !

I tend to choose Bosch.
 
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Originally Posted By: Corvette Owner
From my experience, iridium is the best (and most costly) choice in spark plugs. I took a set out of my daughter's Chevy Malibu after 105,000 miles, they looked NEW ! That convinced me !

I tend to choose Bosch.


While a good choice for a newer engine these aren't the best for an old tractor-like in design I-6. Use Champion coppers or NGK coppers. My 2000 has a sticker on the firewall of the engine bay that says Champion RC12ECC spark plugs are recommended.
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Yep, plain old Champion copper plugs are the way to go... unless you can find those truck plugs.
 
Champion Coppers are the general choice in the 4.0 in the Cherokee, though I believe some of the later ones with COP went to NGKs as factory. Wish the truck plugs were still around - they were my favorites. Not a big deal to replace them every 30k either on this old school engine.
 
i just purchased champion double platinum power premium spark plugs #7034 anyone care to comment before i install them?
 
Don't waste your money on those platinum,iridium,bullcrapitum plugs. Stick with cheap copper plugs and change them every 25000 miles.
As far as plugs go more expensive isn't better. Those platinum,iridium,4 ground strap,split fires can create a misfire because the electrodes get extremely hot and may combust the fuel before the plug fires,then detonation.
I saw a guy at the track use the iridium plugs and it caused a nitrous backfire that blew the hood of his mustang.
There are goods that are worth the added expense. This isn't one of them.
 
Originally Posted By: crazyoildude
i just purchased champion double platinum power premium spark plugs #7034 anyone care to comment before i install them?

Wasted your money.
 
Originally Posted By: crazyoildude
i just purchased champion double platinum power premium spark plugs #7034 anyone care to comment before i install them?


The benefit of long wear metals like platinum is that you won't have to replace or adjust them for over 90k.

It my opinion it is a fair trade off. Put a little grain of rice of silver anti seize on the threads install and forget about them until 90k.
 
I run Autolite AP 985(single platinum)in my I6 Jeep. Last set was changed at 54k and could have gone a little longer.
 
If I read right this jeep uses a DIS (distributorless ignition system) My 2001 wrangler also uses this type of ignition.

Jeeps with this system are actually very picky about what plugs you use. They also wear out much faster then normal because the spark plugs fire every revolution. So there is wasted spark 1/2 of the time.

It is said to stay away from conventional plugs on this system because they will wear out quickly and can cause some weird idling problems.
Using double platinum plugs is the best was to go on DIS equiped vehicles.

here is why: http://www.youtube.com/watch?v=ekCpGSR4oMA&feature=player_embedded

for more info see here:http://www.autolite.com/learn_more/autolite_challenge_videos?select_region=1
 
I always get mushy when I see a Jeep Cherokee post! I miss mine so bad. I had a 2000 Limited with all the options and sold it still in mint condition and running strong back in 2008. Anyway, I always used Autolite Copper plugs since they were so easy to change every 30k miles or so. I once used the Autolite Platinums and they were fine too - but for some reason (maybe in my head) it ran best on plain copper plugs. So my vote is for plain copper autolites.
 
The Jeep 4.0 came with plain jane coppers. My 03 Jeep GC came with NGK V-Power coppers from the factory. The plugs on the 4.0 are real easy to change out. So I don't mind doing them every 30K. IMO anything other that plain coppers in the 4.0 is a waste.

Thats my 2cents.
 
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Coppers will work, i even have coppers in my jeep because I had a starting issue and had the dealer diagnose it all under warranty. they put in factory mopar plugs in and since it was under warrenty (to a separate company) i just kept all the new parts they installed to diagnose what ended up being a leaking fuel injector.

But in a DIS system they will wear out every 30k likie strongt said, but i dont see how using double platinum or iridium is a waste since they will last much longer.

to go 100k miles you could either buy 6 plugs or 18 plugs. So not sure how its wasteful. Its kind of like running synthetic for a longer OCI or conventional in a shorter OCI. Its up to you and what you do with your vehicle to decide.

But since regular plugs will wear out faster and cause mis-firing and poor running conditions alot sooner then others I choose to not use them. (after i need to take out the coppers i have in my jeep now)
 
i have used autolite coppers 985 and the champions listed on the emission stick all w/ no problem. i currently am using the champions on my 99. mike
 
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