Spark Plug Torque Spec?

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GSP

New Member

Apr 8, 2004

55

0

0

Huntsville, Alabama

Apr 13, 2004

#1

• Apr 13, 2004

• #1

I am guessing 18-20 ft-lbs for the aluminum head.

 

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billyfe390

New Member

Aug 18, 2003

573

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0

Apr 13, 2004

#2

• Apr 13, 2004

• #2

14ft/lbs

 

GOLDENPONY

Founding Member

Jan 23, 2002

1,503

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36

LOVELAND, OHIO

Apr 13, 2004

#3

• Apr 13, 2004

• #3

Plug Torque

If you use anti-seize (and you should) I'd reduce that to 10-11 ft/lbs. Also, ALWAYS change your plugs with the engine COLD.

 

Sleepy1

Founding Member

Jun 10, 2002

807

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Chicago, IL

Apr 13, 2004

#4

• Apr 13, 2004

• #4

Where are you guys getting these #'s. 15lbs is hand tight. I would hope your plugs a just a little tighter than that.

 

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Ben99GT

Founding Member

Nov 3, 2002

76

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6

MS Gulf Coast

Apr 13, 2004

#5

• Apr 13, 2004

• #5

10-11 ft.-lbs. is right. 15 is too much...

 

GOLDENPONY

Founding Member

Jan 23, 2002

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LOVELAND, OHIO

Apr 13, 2004

#6

• Apr 13, 2004

• #6

Spark plug torque

This number comes straight from the Ford maintenence manual

 

JCKnife

Founding Member

Feb 21, 2002

602

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Ohio

Apr 13, 2004

#7

• Apr 13, 2004

• #7

If I remember right the Haynes manual said 11-13 ft. lbs. with the use of anti-seize on the threads.

 

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bdcardinal

tree hugger

Jun 10, 2003

3,612

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69

santa barbara, CA

Apr 14, 2004

#8

• Apr 14, 2004

• #8

on the box that my autolites came in it said to tighten then hand tight, then go 1/16th of a turn more. that would probably get to 11-13ft-lbs.

 

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46gtsblown

Founding Member

Jan 9, 2002

278

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Apr 14, 2004

#9

• Apr 14, 2004

• #9

I just go by the tried and true, do it with the motor cold, use anti seize and tighten them up snug with a tweek.
It has worked for me for 25 yrs without any stripped threads or stuck plugs.

Dwayne

 

9

92blustang

Founding Member

Jul 13, 2002

73

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0

Mar 2, 2011

#10

• Mar 2, 2011

• #10

46gtsblown said:

I just go by the tried and true, do it with the motor cold, use anti seize and tighten them up snug with a tweek.
It has worked for me for 25 yrs without any stripped threads or stuck plugs.

Dwayne

Click to expand...

That may have worked in the last 25 years, but these NEWER technology MOD motors are different from the ol pushrod simplistic iron head motors of yester-year that do fine with tightening the plugs by feel with NO probs ever.

There is a very FINE line with tightening the plugs on these 4.6 motors and ya BETTER get it RIGHT or you are going to have to deal with spark plug blowout. All because some knucklehead engineer at Ford decided that 3 threads was enough in the heads of the 99-2003 year 4.6 mustangs.

That engineer should've been fired and be forced to have to pay Ford BACK for this HUUUGE GOOF-UP that occurred on his watch that MANY poor customers had to FOOT THE BILL COMPLETELY for the repairs many of which were COSTLY. What a knucklehead this engineer is... complete knucklehead...

(And YES I dug up an old thread here, but I felt it worth mentioning this here being that this thread is still available for folks to read here.)

 

Reactions: Loose nut

trinity_gt

10 Year Member

Jan 31, 2003

3,125

81

99

Canada

Mar 2, 2011

#11

• Mar 2, 2011

• #11

Yes, the torque specification is quite low (~13 ft-lbs). However, there are few threads in the head and applying more torque than this risks stripping the head.

There is also a risk of plugs backing out over time and "blowing out."

Points:

• the heads are aluminum so use good anti-seize to prevent galling
• only perform plug work on a cold engine
• stick with the factory torque specification
• because the factory torque spec is so low, consider using an in-lb torque wrench for increased accuracy (13 ft-lbs == 156 in-lbs)
• go back and check the plug torque after a hundred miles or so (engine cold)
• consider checking the plugs for tightness at least a couple of times a season to catch any that may be in the process of backing out

 

LarsD

Founding Member

Jul 2, 2002

2,680

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123

Texas

Mar 6, 2011

#12

• Mar 6, 2011

• #12

Did the DOHC motors have the spark blowout problem also?

 

trinity_gt

10 Year Member

Jan 31, 2003

3,125

81

99

Canada

Mar 6, 2011

#13

• Mar 6, 2011

• #13

LarsD said:

Did the DOHC motors have the spark blowout problem also?

Click to expand...

I don't believe so.

 

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bdcardinal

tree hugger

Jun 10, 2003

3,612

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69

santa barbara, CA

Mar 6, 2011

#14

• Mar 6, 2011

• #14

trinity_gt said:

I don't believe so.

Click to expand...

They do blow out, but its not as common. I had a talk with a Ford Field Service Engineer about anti-seize on plugs, some interesting insight from the mother ship about not using it.