Time for spark plugs What should I use? - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ Tech Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 01-31-2011, 08:20 AM   #1
Jeeper
 
drl650's Avatar
 
Join Date: Dec 2010
Posts: 281
Time for spark plugs What should I use?

My 04 Rubicon is in need of new plugs..Who uses which plugs. Looking for any advice.Also what gap do I need? Thanks.

drl650 is offline   Quote Quick Reply
Old 01-31-2011, 09:21 AM   #2
Jeeper
 
uppidycon's Avatar
 
Join Date: Jan 2011
Location: Dayton, Tx
Posts: 118
if the engine is stock, then i'd say go back with OEM.. they are good enough from factory and have worked well this long..

__________________
2004 Jeep Wrangler
6" Full Traction LA Lift
37" Pit Bull Rockers
AWESOME!
uppidycon is offline   Quote Quick Reply
Old 01-31-2011, 09:33 AM   #3
Knows a couple things...

WF Supporting Member
 
Jerry Bransford's Avatar
 
Join Date: Nov 2005
Location: Escondido, Calif.
Posts: 31,557
Images: 2
Newer DIS (distributorless ignition system) 4.0L engines like used on 2001 and newer 4.0L engines are VERY picky about their spark plugs. Installing the wrong type of plugs... most notable single-tipped spark plugs like Autolite's AP-985 or Champion's 3034... will ultimately cause the engine to start running rough after a while.

DIS engines like in your '04 Rubcion run best and the longest with double-tipped platinum plugs like the Autolite APP-985 or Champion 7034. Or the Autolite XP-985 which is iridium tipped. Any of those three plugs will give you over 100K miles of very good performance.

You could also run the OE model spark plugs which are conventional plugs with no platinum coating. The only issue with them is you'll have to change them about 4x as often as the platinum or iridium spark plugs. The DIS ignition fires the spark plugs twice as often as normal so conventional plugs only last half as long as they do with conventional ignition systems. So if conventional plugs would normally last 25-30K miles, they'll maybe last 15K miles with the DIS ignition like your '04 has.

So for your Rubicon, I would definitely only use the dual-tipped platinum Champion 7034 or Autolite APP-985, or the iridium Autolite XP-985 and then you can forget about needing spark plugs for another 100K miles. Really.
__________________
Remember that having a different opinion doesn't also require one to be a jerk when expressing it.

When you have a choice, buy American.

Jerry Bransford is online now   Quote Quick Reply
Old 01-31-2011, 11:25 AM   #4
Jeeper
 
Join Date: Aug 2008
Posts: 2,473
Don't let the parts houses try to sell you anything other than what Jerry said or what's on the underhood label - it also shows the gap.

Parts houses will recommend all kinds of other stuff because they get commissions or "attaboys."
__________________
It's no wonder the country is falling apart - stupidity abounds!
rrich is offline   Quote Quick Reply
Old 01-31-2011, 12:51 PM   #5
Newb
 
Join Date: Jan 2011
Posts: 7
Quote:
Originally Posted by rrich View Post
Don't let the parts houses try to sell you anything other than what Jerry said or what's on the underhood label - it also shows the gap.

Parts houses will recommend all kinds of other stuff because they get commissions or "attaboys."

I messed around and went with the new E3 plugs and had all sorts of performance issues (engine stalling and bucking) the day I changed them. Not knocking E3, but my stock 4.0L engine definitely does not need some crazy high performance stuff. Went back to Autolite XP Iridium plugs and have had no problems since.
justin.simonitsch is offline   Quote Quick Reply
Old 01-31-2011, 01:17 PM   #6
Jeeper
 
drl650's Avatar
 
Join Date: Dec 2010
Posts: 281
I went with Champion crossed reference the factory NGK plugs..The origional plugs has 49k miles never been replaced. The gap on the factory plugs were between 0.039 and 0.041.. The electrode was worn down...New plugs installed all at 0.035 and it seems to idle and run much smoother.

drl650 is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
10 Best Car Repair Tools of All Time larphead General Jeep Discussion 14 07-24-2009 05:29 PM
Meet Cory the well driller (political) skeeter Off-Topic 5 10-30-2008 02:54 PM



» Featured Product

All times are GMT -5. The time now is 03:45 PM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC