Too much torque on spark plugs 03 F150 4.6 V8?
04-10-2014, 11:40 PM
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Too much torque on spark plugs 03 F150 4.6 V8?
I recently bought a 2003 F150, 4.6 V8, 115K miles. Prior owner never changed the spark plugs, so I just did that. I think I over torqued the new plugs @ 28 ft/lbs with antiseize. I used motorcraft nickel plugs gapped to .054.
Chilton's (ch1-29) says 14 ft/lbs with antiseize for 97-03. I saw some threads online (e.g.,
https://www.f150forum.com/f72/97-03-...-93389/index3/ ) where it said to do 28-32 ft/lbs to avoid the blowout problem, notwithstanding the manuals. Also, there's a Ford TSB that says the 4.6 V8 through 2003 was covered by that blowout defect.
So I torqued to 28 ft/lbs with antiseize. That was last weekend.
Today I noticed that the 28 ft/lbs was dry. With antiseize being a lubricant that would mean I exceeded the compression of 28 ft/lbs on the threads. Nothing stripped when I put it in. But wondering when the engine expands from heating, will that ruin the thread? At this point what do I do, re-torque them to like 20 ft/lbs? Or is it better to just leave well enough alone and change them ahead of schedule in like 20K miles, since they're just nickel plugs anyway.
I used a spark plug socket coated with rubber on the inside where it touches the porcelain of the plug when I torqued.
Chilton's (ch1-29) says 14 ft/lbs with antiseize for 97-03. I saw some threads online (e.g.,
https://www.f150forum.com/f72/97-03-...-93389/index3/ ) where it said to do 28-32 ft/lbs to avoid the blowout problem, notwithstanding the manuals. Also, there's a Ford TSB that says the 4.6 V8 through 2003 was covered by that blowout defect.
So I torqued to 28 ft/lbs with antiseize. That was last weekend.
Today I noticed that the 28 ft/lbs was dry. With antiseize being a lubricant that would mean I exceeded the compression of 28 ft/lbs on the threads. Nothing stripped when I put it in. But wondering when the engine expands from heating, will that ruin the thread? At this point what do I do, re-torque them to like 20 ft/lbs? Or is it better to just leave well enough alone and change them ahead of schedule in like 20K miles, since they're just nickel plugs anyway.
I used a spark plug socket coated with rubber on the inside where it touches the porcelain of the plug when I torqued.
04-11-2014, 08:29 AM
#2
Senior Member
Just leave them alone, the heads have been tested at much higher torque than that.
