spark plugs

[myeddiebauer]

@ 86k I want to replace spark plugs. any recommendations as to brand ?
also is the 4.0 v-6 aluminum or have aluminum heads and what are torque specs

 

[Number4]

Get Iridiums. I use Autolite or Champion, but you could get Denso, NGK or Motorcraft.

Stay away from anything with multiple grounds electrodes.
Split fires/ rapid fires/ +4's & +2's.

 

[apenland01]

The stock Motorcraft plug is great, so are the Autolite Iridium's, which is what I recently used. My torque was listed at 13ftlb, but I went 20 based on some recommendations that it was simply too low at 13.

Number4's recommendations of what to avoid are spot on.

 

[Tyleryac]

I use and recommend Motorcraft

 

[swshawaii]

Motorcraft SP500 Finewire Platinum, Autolite APP103 Double Platinum, or XP103 Iridium. Carefully check gaps at .054" and lightly coat the threads with copper or nickel anti seize. I assume these are the original plugs being replaced at 86k that have never given issues. Reading counless threads, why change from OEM plugs that are proven to work well for so long?

http://www.rockauto.com/catalog/x,carcode,1377660,parttype,7212

 

[Number4]

When I pulled my original plugs from my '05 4.0, the gaps were ridiculous. Instead of .54 I believe some were around .70, it was no wonder my gas mileage went from 13 to 17 after replacing them. Based on my findings, I'd suggest replacing them at least every 70k.

I also believe the OEs were only platinum on one side, not both. Either way they were far from spec.

I don't know that the 4.0 heads have the same concerns as the 4.6 heads, but I have to respectfully disagree with [MENTION=106710]swshawaii[/MENTION] on the antiseize.

The torque on the plugs isn't much and torque settings are based on resistance. Putting antiseize on the threads reduces torque. So dry 13' lbs is different than lubed 13' lbs. what you'll do, is end up over torquing.

Now, I did use some antiseize, but I only placed it at the end of the threads were they'd be exposed to the elements. To help stop corrosion at that point.

 

[leadfootdriver]

My ride was beginning to have hard starts after the motor was warmed up; most likely due to the increased gaps at 96K miles. But I just went with Motorcrafts. The price was right, they are proven, and I'll probably never need to change them again.