Originally Posted by Bustedknuckle

It's okay, we can turn this ship around and get her pointed in the correct direction. We'll call this the official -

"Newb who signed up today to ask 1 question but wants to know exactly about his specific need thread instead of searching."

Thread.

So... deep breath... ready?

Also consider changing out your plug wires, as they have seen just as much wear and tear as the rest of the electrical system. Changing them out with a standard plug wire will be fine, either via Mopar from your local Dealer or Autolite seems to be a popular choice for O.E fitment (<- there's that word again!)

Next, as preventative maintenance, consider changing the distributor cap and rotor, seeing as they too have probably seen 142000 miles at this point. Also, given your exact climate, it might be a good notion to replace or at least purchase an ignition coil for spare or instant installation. Why? Because an ignition coil changes your 12v system to the required 150,000 to 170,000 volts required to achieve correct spark. It achieves this by simply spinning a copper wire around a magnet. But given the fact you absolutely love your XJ, I assume your already sold.

Other points of interest would include a fuel filter, air filter, transmission filter kit, flushing all fluids, i.e Coolant, transmission oil, front and rear gear oil, power steering fluid, brake fluid (D.O.T 3 or whatever you choose to supersede it). When changing differential fluid, be sure to add Mopar LSD additive, available at your local dealer for under $10 with tax.

Doing all that you will see another 100 trillion miles out of your beloved XJ.

Welcome to the cereal bowl, please stick around for the cookies and pie. We're a fun bunch.

Originally Posted by Evilpopcorn

Like others have said, stick with the Champions, Jeep's engineer's worked countless hours to see what plug is best, they ended up with Champion. And great job making us XJ owners sound like a bunch of douchebags guys, educate, don't hate. Poking fun is all fine and good (Please, change where you say V6, it's a STRAIGHT 6, or INLINE 6, as in I6). If someone doesn't know, they don't know, ignorance isn't idiocy.
Anyways, back to you OP, welcome to CF, don't worry, I'm sure you'll become a grease-monkey pretty soon, I didn't even know what a differential was when I first got mine, now I can do quite a bit myself. Try changing the plugs yourself, it's actually pretty easy, just make sure to gap them correctly, just ask around, trust me, you can't beat that great feeling you get when you did something YOURSELF, rather than take it to a mechanic. Here's a couple books that will REALLY help you get started-
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Jeep-Cherokee-Wagoneer-%2784-%2701-Repair-Manual-Haynes_6060072-P_626_R|GRPBOOKS_775256726____
http://www.amazon.com/High-Performan.../dp/1932494146
https://www.techauthority.com/en-US/...px?itemID=1270
Last one is kind of expensive, but it makes the Haynes manual look like a pamphlet.

Originally Posted by 1991Jeep_Man

I thought someone also told me NGK's were good for the 4.0 as well? Just stay away from those Bosch platinum blah blah and those Pulseplugs blah blah and E3 blah crap. The 4.0 wasn't designed for any of that. And MANY times agreed with Defiance. Be careful with those plugs. Nice, even but firm pressure to loosen them. Be sure to add anti-seize to the new plugs.

Originally Posted by Bologna

Anti-seize? Never heard of it but I will put some sort of lubricant on it first, thanks.

Originally Posted by Defiance665

not "some sort of lubricant"... Antiseize.

Originally Posted by 1991Jeep_Man

Wherever you buy your plugs, ask them for some spark plug anti-seize. I know A/Z recommends it with the purchase. It's just a little package, but a great assurance. They should know what you're needing. If not, I would question their know-how.

Edit: this stuff. http://www.autozone.com/autozone/acc...ier=196158_0_0_

Originally Posted by Evilpopcorn

Like others have said, stick with the Champions, Jeep's engineer's worked countless hours to see what plug is best, they ended up with Champion. And great job making us XJ owners sound like a bunch of douchebags guys, educate, don't hate. Poking fun is all fine and good (Please, change where you say V6, it's a STRAIGHT 6, or INLINE 6, as in I6). If someone doesn't know, they don't know, ignorance isn't idiocy.
Anyways, back to you OP, welcome to CF, don't worry, I'm sure you'll become a grease-monkey pretty soon, I didn't even know what a differential was when I first got mine, now I can do quite a bit myself. Try changing the plugs yourself, it's actually pretty easy, just make sure to gap them correctly, just ask around, trust me, you can't beat that great feeling you get when you did something YOURSELF, rather than take it to a mechanic. Here's a couple books that will REALLY help you get started-
http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_Jeep-Cherokee-Wagoneer-%2784-%2701-Repair-Manual-Haynes_6060072-P_626_R|GRPBOOKS_775256726____
http://www.amazon.com/High-Performan.../dp/1932494146
https://www.techauthority.com/en-US/...px?itemID=1270
Last one is kind of expensive, but it makes the Haynes manual look like a pamphlet.