Spark Plug Confusion - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum



Welcome Enthusiast! If you already own a Chevy TrailBlazer or GMC Envoy or perhaps thinking of purchasing such a vehicle, then you have come to the best TrailBlazer and Envoy site on the net! Rainier, Bravada, Ascender, and 9-7x owners welcome too!

You are currently viewing our site as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to search and post topics, communicate privately with other members, respond to polls, upload content, and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.
Join Today!
Go Back   Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum > 2002 - 2009 TrailBlazer/Envoy Tech > 02-09 Vortec 4.2L I-6 Engine and Drivetrain

02-09 Vortec 4.2L I-6 Engine and Drivetrain Q&A forum for engine and drivetrain repairs/modifications/tuning.

TrailVoy.com is the premier GMC Envoy Forum on the internet. Registered Users do not see the above ads.
 
 
Thread Tools
  #1  
Old 09-20-2006, 02:14 PM
RozmerJJ's Avatar
RozmerJJ RozmerJJ is offline
Senior Member
 
2005 Chevy TrailBlazer LS
Silverstone Metallic 4.2L I6 4X4
Join Date: Apr 2006
Location: Delaware, Ohio
Posts: 572
Question Spark Plug Confusion

I'm getting ready to change the plugs in my 02' TB and looked the part up on the AC Delco site and got 2 plugs listed. I have also seen 3 different gap settings for this year.

Plug #'s : 41-965 and 41-981

Question 1) Which is the correct plug for the 02 I6???????

Question 2) What is the correct gap? 0.050, 0.049 or 0.043?????
Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old 09-20-2006, 02:49 PM
tblazed's Avatar
tblazed tblazed is offline
Basic Vendor- DRL Killer
 
2002 Chevy TrailBlazer LS
Summit White 4.2L I6 2WD
Join Date: Sep 2004
Location: DFW - The Republic of Texas
Posts: 2,212
The 41-965 was used only with the 2002 4.2 i6. The 41-981 applies to many engines not just the i6, so what I've concluded is, ACDelco is eliminating that unique 41-965 plug replacing it with the more common 41-981. ACDelco within the last 6 months added the 41-981 to the list for 2002 as the '965 plug seems to be going away. ACD has had inconsistent gap specs on their web site since I first looked it up in back 2003.

I have been running a set 41-981 plugs with .043 gaps in my 2002 for a couple of years. I believe the old spec .050 gap does not produce as stable of a spark at WOT 6,100 rpm as a .043 gap. When I took out the original '965s they all measured .042 to .043. Another reason I went with the .043 is the coils will not have to develop such a high voltage to jump the gap, reducing the possibility of coil failure. Engine runs and idles perfectly, zero misfires with 41-981 at the .043 gap they come with.

My 3¢.
Quick reply to this message
  #3  
Old 09-20-2006, 03:04 PM
Crossroader Crossroader is offline
Member
 
Join Date: Jul 2006
Posts: 204
Confusing, ain't it?

You're not the only one confused. I'm getting ready to change the plugs and am in the same boat.

I went to the dealer and asked what plug and gap to use. They referred me to the AC Delco 41-965 with a gap of .049. I asked about the 41-981 being used for the 02 and they didn't have any info for it. They just said it was for the 03 and later.

As tblazed says, AC Delco is showing both parts for the 02. However, I do not know that they are eliminating 41-965 for our vehicle. Also as he said, AC Delco has had different gaps listed on their site for the 41-965.

Edit: I'll probably end using the new plug 41-981 with .043 gap.
Quick reply to this message
  #4  
Old 09-20-2006, 03:15 PM
RozmerJJ's Avatar
RozmerJJ RozmerJJ is offline
Senior Member
 
2005 Chevy TrailBlazer LS
Silverstone Metallic 4.2L I6 4X4
Join Date: Apr 2006
Location: Delaware, Ohio
Posts: 572
Thanx for all the info!

I went with the 41-965 because I found them on the internet for the same price as the 981's and free shipping to boot.

I will use the .043 gap unless someone really tells me to do otherwise and has info to back it up.
Quick reply to this message
  #5  
Old 09-27-2006, 09:26 AM
MichEnvoyBoy's Avatar
MichEnvoyBoy MichEnvoyBoy is offline
TrailVoy Alumni
 
2002 GMC Envoy SLT
Midnight Blue Metallic 4.2L I6 4X4
Join Date: Aug 2005
Location: Midwest
Posts: 1,282
Would you mind sharing where you got the spark plugs at with the free shipping?

Im having trouble finding them on the 'net without paying an arm or a leg for the plugs, or having to have a $50 min. order to get free shipping.
__________________
"Envoyaholic"
2002 Envoy SLT Autoride, Navigation, Dark Blue. 152,000 miles. Purchased 10/2004
Quick reply to this message
  #6  
Old 09-27-2006, 01:30 PM
RozmerJJ's Avatar
RozmerJJ RozmerJJ is offline
Senior Member
 
2005 Chevy TrailBlazer LS
Silverstone Metallic 4.2L I6 4X4
Join Date: Apr 2006
Location: Delaware, Ohio
Posts: 572
Quote:
Originally Posted by MichEnvoyBoy View Post
Would you mind sharing where you got the spark plugs at with the free shipping?

Im having trouble finding them on the 'net without paying an arm or a leg for the plugs, or having to have a $50 min. order to get free shipping.

I used autopartsgiant.com and ther was a $50.00 min order but I also needed to replace my fule filter and serp belt.
Quick reply to this message
Sponsored Links
Advertisement
 
 

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum forums, you must first register.

Please enter your desired user name, your email address and other required details in the form below.
(Only letters, numbers, dashes and underscores are permitted for user names)
The user name that you choose is permanent and can never be changed.
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.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
New Spark Plug Information for the 4.2L I6 Crossroader General 38 06-18-2013 03:18 PM
tricks to spark plug installation?? tbmdsd OEM Issues 9 04-29-2011 02:18 PM
Big Problem New to TB General 24 09-09-2010 02:58 PM
Is this the spark-plug you all are using? rbarrios General 17 10-11-2008 02:02 AM
Using spark plug to break windsheild ieatglue Everything Off-Topic 24 03-04-2006 07:56 PM


» Sponsors

Advertising Info

All times are GMT -4. The time now is 07:37 PM.


Chevy TrailBlazer and GMC Envoy Enthusiasts - Copyright 2004 - 2009 All Rights Reserved.
All trademarks referenced herein are property of their respective owners.
RSS Feed