Spark Plug Torque Spec?

[GSP]

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

 

[billyfe390]

14ft/lbs

 

[GOLDENPONY]

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]

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

 

[Ben99GT]

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

 

[GOLDENPONY]

Spark plug torque

This number comes straight from the Ford maintenence manual

 

[JCKnife]

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

 

[bdcardinal]

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.

 

[46gtsblown]

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

 

[92blustang]

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

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.)

 

[trinity_gt]

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]

Did the DOHC motors have the spark blowout problem also?

 

[trinity_gt]

Did the DOHC motors have the spark blowout problem also?

I don't believe so.

 

[bdcardinal]

I don't believe so.

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.