I've always run the factory NGK's. No issues whatsoever.

 

I agree.

most problems come from aftermarket plugs. Splitfires, cheap replacements, etc... Not to say you can't get a bad NGK out of the box, but I stick with what works. As for the autolites, thats what I use in my fords.

 

I'll assume from the 04 that you have an 04 TJ. I've been using Autolite APP985s for about 10,000 miles since replacing the OEM plugs with no issues.

 

Thread link on discussion of plugs. Jerry's very knowledgeable when it comes to this.

http://www.wranglerforum.com/f5/new-plugs-87640.html

 

Funny I just finished tuning up the wifey's. I went with Bosch Platinum's.

I pulled I swear the originals out (136000 miles) as the wires/cap/rotor were all mopar.
We just bought it, so it needed it. Plugs were worn down to nearly a 60 thos. gap, center electrode was just barely visible.

 

I replaced the factory plugs with Champion 7034 plugs about 6,000 miles ago. No issues or problems what-so-ever. I really like them.

When putting the coil rail back on, make sure you get the boots completely over the plugs - it sounds elementary, but it's much easier said than done.

 

Champion 7034, Autolite APP985, or factory NGK's will work just fine.

Caution: do NOT buy single platinum plugs. they don't work in distributorless ignition systems used on newer model TJ's.

 

Auto Zone currently has a good rebate on Autolite plugs. I just installed Autolite APP985 in my '01 4.0 Sahara. Cost $4.49/each with $1.50 rebate each. Seems to start quicker and idles smoother than the Bosh platnums I'd had in there the last 30,000 miles. Haven't driven enough to tell much else about them.

 

I have a buddy that currently works for an independent auto shop. He used to work for Chrysler, he still recommends what came in it factory. Says for some reason the 4.0 can be picky...

 

The 2000 and newer 4.0L is indeed very picky about the spark plugs it runs on due to its DIS (distributorless ignition system). It fires on both the compression and exhaust stroke which places additional demands on the spark plugs.

Because the spark plugs fire twice as often with a DIS-equipped 4.0L engine, conventional spark plugs like the NGKs a few keep recommending will only last half as long in the newer DIS engines as they would in an older non-DIS engine. Personally, I would only run dual-tipped platinum like the Autolite APP-985 or Champion 7034 or the new iridium style spark plugs like Autolite's XP-985 in newer DIS engines.

 

I vote Autolite....I have had zero luck with anything champion makes

 

I almost agree with the above.

Only difference is my '65 Olds Cutlass F-85 doesn't like Autolite at all. Never had any problems with Autolite in any other GM's I've owned in my life.

 

Conventional spark plugs like the NGKs will work fine in the newer DIS engines but they will erode their spark plug gap at twice the rate on a newer DIS engine as they would in an older engine. That simply means a conventional spark plug will only last half as long in a DIS-equipped 4.0L engine made 2000 and later than it would in an older engine. That's why I don't recommend any conventional spark plugs in newer 4.0L engines. Dual-tipped platinum or the latest iridium tipped spark plugs will easily exceed 100K miles without spark plug gap growth which means the engine will run well on the same set of dual-tipped platinum or iridium tipped plugs for 100k miles. Conventional plugs will typically only get 15-20K miles before needing to be replaced.

 

NGK's are what came in my Jeep from the factory and everyone that uses them has not had any problems that I have heard of.

 

Thanks for all the help, after doing some research I went back with the NGK plugs, my Jeep has 88,000 miles on it and from the looks of the plugs I removed that was the first time they had been changed (had about a .80 gap) It ran good before the change but much better now, silky smooth. Hopefully my mileage will go up a tad!

 

The following is purely the opinion of the user:

Don't put Autolite plugs in your Jeep. Autolite is made by allied signal, who makes Fram and Fram is crap. If you want a real spark plug, use Champion.

NGK? Really? You're gonna put rice junk in your American engine? You might as well put wasabi on your spaghetti while you're at it.

If it's not American, it doesn't go anywhere near my TJ.

Couple it with Borg Warner wires.

 

The following is purely the opinion of the user:

Don't put Autolite plugs in your Jeep. Autolite is made by allied signal

Right. :nonono: Autolite's spark plugs are no more made by Allied Signal (who owns Autolite) than BFG tires are made by Michelin who owns BFG. Like BFG and their American made BFG tires that aren't made in France by Michelin who owns BFG, Autolite's spark plugs are made right here in the U.S. in the same Autolite plant and workers who were there before they were bought by Allied Signal.

 

The following is purely the opinion of the user:

Don't put Autolite plugs in your Jeep. Autolite is made by allied signal, who makes Fram and Fram is crap. If you want a real spark plug, use Champion.

NGK? Really? You're gonna put rice junk in your American engine? You might as well put wasabi on your spaghetti while you're at it.

If it's not American, it doesn't go anywhere near my TJ.

Couple it with Borg Warner wires.

Haha wasabi on spaghetti =P ahaha!

 

Champion. Change them every 30,000 or so for best performance. You don't need to buy expensive plugs or high octane gas.

 

Post #15 """""Thanks for all the help, after doing some research I went back with the NGK plugs, my Jeep has 88,000 miles on it and from the looks of the plugs I removed that was the first time they had been changed (had about a .80 gap) It ran good before the change but much better now, silky smooth. Hopefully my mileage will go up a tad! """""


Kinda shoots down the hype about using Autolite plugs designed for a PT Cruiser.

The under hood label was written by the people that made your engine. You'd think they'd know.

Honeywell no longer owns either Fram or Autolite. As with most flim-flam products, they get sold before the lawsuits catch up with them.

Check Wikipedia.

 

Honeywell no longer owns either Fram or Autolite. As with most flim-flam products, they get sold before the lawsuits catch up with them.

Check Wikipedia.

Then why can you go to the honeywell website and go to their products and both fram AND autolite show up? Also the fram and autolite websites make note of a "honeywell car care product" at the bottom of their sites...

Wikipedia isnt the most reliable resource anyways...but in this case...check these out...honeywell

http://en.wikipedia.org/wiki/Fram_(oil_filter)

http://en.wikipedia.org/wiki/AlliedSignal

 

The Autolite plain 985's are made in China and the APP985's Mexico. I finally found some Champion 4412 truck plugs (I have a distributor), and they're made in the U.S. of A. I'm not sure if they were old stock, some say they're discontinued. My '99 loves 'em.

 

I have 6 brand new in the box Champion 4412 plugs that I would almost pay someone to take. They do not work well in my 2006 LJ. I know the older 4.0L Jeeps swear by them.

 

Wow!

 

Did you catch all that, mrclean ? We're gonna quiz you

 

Jerry, youve been talking about the post 2000 engines. I've got a 1998 and I need new plugs soon. What kind do you think are best for my 4.0?

 

Champion's 3034 and Autolite's AP-985 will both perform well in your distributor equipped 4.0L for over 100K miles. Both are single-tipped platinum plugs that work well in your non-fussy engine.

 

Jerry - read post #15
HE WENT BACK TO NGK'S AFTER GETTING 80,000 MILES ON THE ORIGINAL ONES.

Note the use of the word BACK!

You claim standard plus only last a short time - do you need to be quoted on that?


Honeywell is in the process of selling their interest in Fram - it will be finalized 3rd qtr 2011. Corporate razzle-dazzle to confuse the lawyers.

Google it!

 

No plug with a .08 gap has "lasted" 80,000 miles. That's like saying tires so worn out that their steel plies are showing are still ok because they still hold air. No one with a lick of common sense would say a plug with a .08 gap was still ok. A dual-tipped platinum plug will still have its .035 gap at 100K miles.

 

My NGK's in my 2006 LJ, from the factory, lasted 93,000 miles and the only reason they did not last longer was because I had the dreaded OPDA problem and a 4.6L stroker is being put in my heap to fix that as we speak. Guess which spark plugs my mechanic's using? NGK's.
The last few years of the 4.0L likes the NGK's.

 

He He - so are we to assume the last 50,000 miles he put on it was on the back of a tow truck?

It was still running up till he decided to replace them. No?

Since he got good service from them, he "went back" to NGK's, same as it had before. READ HIS POST!

Sure 80,000 miles is pushing it, but it obviously worked fine.

Autolite and others have been around a long time, as well as many other "gimmick" plugs. If Jeep thought they'd be better they'd use them and call them out. But they don't. In the quantity they use, the price difference wouldn't be much, and I'm sure Autolite would love it if they were the recommended supplier - they'd sell many more than you sell for them.

Changing plugs occasionally is just routine maintenance, like changing oil, washing your windows etc. It gives the chance to see how the cylinders are burning, and it's easy and cheap.

But some of the gimmick plugs do work in some applications, - Bosch, Autolite, and others wouldn't still be in business if they didn't. Slick 50, Wynn's Friction Proofing, Hudsons, Doble Steamers, Franklins, and Yugos worked too, but where are they now?

 

Today..............I put in a set of Autolite AP985's wow, smooth as silk, a bit more power coming up through the gears

Bosch was what was in it, they looked perfect, so we'll see

 

Nice, what model year TJ and which engine?

 

I just bought a super clean '95 Cherokee - wouldn't pass smog with the rough idle. 4.0 with a distributor.
It had almost new Denso plugs in it. I went with what the underhood label said to use, Champion 12YC. Idles fine now.

After my experience with Autojunk plugs in my motorhome - never again!

I put the Autojunk double plat plugs in my Rubi - seems to still run OK - it has almost 300 miles on the plugs now.

 

for 2000+ champion 7034 NOT 3034