Spark plugs - torque wrench, or finger tight plus quarter turn? - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Liberty Forums > KJ Liberty Forum > Spark plugs - torque wrench, or finger tight plus quarter turn?

Savvy Aluminum BumpersIntroducing MONSTALINER™ UV Permanent DIY Roll On Bed LineThe RuffStuff "I can't go to EJS" Sale!

Reply
Unread 04-11-2013, 12:51 PM   #1
AVR2
Registered User
1993 ZJ 
 
Join Date: Apr 2007
Location: UK
Posts: 1,944
Spark plugs - torque wrench, or finger tight plus quarter turn?

I'm going to change the plugs in my 2005 KJ for the first time over the weekend - I've always had it done by a garage before. I have the Mopar plugs, and there's a little diagram on the box that seems to be indicating that you should get them finger tight and then a quarter turn with the ratchet.

Is that the best way, or should I use a torque wrench? (I'm assuming that there's a torque spec in the FSM, just haven't looked yet). I'm used to using a torque wrench for plugs, but then I've only changed them on the iron-head 4.0L before, not an aluminium head.

AVR2 is offline   Reply With Quote
Unread 04-11-2013, 01:19 PM   #2
jbarthol
Registered User
2005 KJ Liberty 
 
Join Date: Nov 2012
Location: Cedar Falls, Iowa
Posts: 119
Make sure they are the same model number as that identified on the sticker. I hand tightened them, then a half turn after that.
jbarthol is offline   Reply With Quote
Unread 04-12-2013, 09:39 AM   #3
Georgeandkira
Registered User
 
Join Date: Sep 2010
Location: Hackensack,NJ
Posts: 21
Apologies Ahead of Time....

Hello, Sorry to sound like an authority figure. I'm brand new to Liberties. I've yet to see the plugs; so I'm learning too. Try to find a torque value or other spec for plugs in an aluminum head. The box many spark plugs came in had a pictogram. Plugs with a crush gasket had a quarter turn (90º) picture. You could turn them more but why do that? Bevel edged, non-gasketed plugs had an eighth turn (45º) picture. Anyone would have to be nuts to go more. I'd make darn sure of any instruction to go a half turn (180º) beyond contact; ESPECIALLY in an aluminum head. Like I said, you can crush a washer way-way down if there is one; but why do that? I never had any problem following the 1/4 turn-1/8 turn guideline. Feel free to sign on and call me names. Kira
Georgeandkira is offline   Reply With Quote
Unread 04-12-2013, 09:52 AM   #4
jbarthol
Registered User
2005 KJ Liberty 
 
Join Date: Nov 2012
Location: Cedar Falls, Iowa
Posts: 119
This is what NGK instructs to do.
"4. Tighten the spark plug finger tight first until the gasket reaches the cylinder head, then screw about ½ - ¾ turn more with a plug wrench. (Conical seat; about 1/16 turn more)."
jbarthol is offline   Reply With Quote
Unread 04-12-2013, 10:20 AM   #5
DaveJKJ
Registered User
2005 KJ Liberty 
 
Join Date: Nov 2008
Location: stuck in the mud again
Posts: 1,059
I always snug mine up by hand and then snap my ratchet on the extension and 1/4 turn.
__________________
War Veterans Jeep Group #31
Black Jeep Society #217
DaveJKJ is offline   Reply With Quote
Unread 04-12-2013, 01:03 PM   #6
AVR2
Registered User
1993 ZJ 
 
Join Date: Apr 2007
Location: UK
Posts: 1,944
I checked the box again, and it actually says to get the plug finger-tight and then a half- to two-thirds turn with the ratchet. These are the proper (overpriced) Mopar-branded plugs from the dealer.

So I gave them all a half-turn.
AVR2 is offline   Reply With Quote
Unread 04-14-2013, 04:01 PM   #7
Eicas
Registered User
2006 KJ Liberty 
 
Join Date: Apr 2013
Location: University Place, WA
Posts: 5
I use a torque wrench.

Too loose and the plug runs hot from inadequate heat transfer, or may leak, too tight and you damage the internals and throw the gap off. Why take a chance?

I never install a plug without checking the gap, my last new set varied, - so all but 2 had to be adjusted.
Eicas is offline   Reply With Quote
Unread 04-19-2013, 10:44 PM   #8
DarkSport11
Registered User
2011 KK Liberty 
 
Join Date: Mar 2013
Location: Farmingville, New York
Posts: 145
I tighten mine by hand with a socket that has an extension attached to it until the plug seats against the head and then I tighten it to specs with a torque wrench.
DarkSport11 is offline   Reply With Quote
Unread 04-20-2013, 05:47 PM   #9
Trombino
Registered User
1978 CJ7 
 
Join Date: Nov 2005
Location: Rochester, NY
Posts: 1,588
I believe the FSM says 20 ft. lbs. and don't forget to use some anti-seize compound.
__________________
'78 CJ7 -- Chevy 350 SBC, Holley 4-BBL, TH700R4, B&M Performance Shifter, Dana 300 w/ Twin Sticks, 3" Shackle Lift, 3" Body Lift, D30 Front (Disc), AMC 20 Rear w/ Moser 1-Piece, 4.10's, 35x12.50/15 General Grabber MT's, Cragar Soft 8's (15x8 w/ 4" BS)
Trombino is offline   Reply With Quote




Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.