I'm replacing the plugs in my 03 F150 4.2L. My book says the spark plug gap is .054, but that's for the OEM plugs. I bought Autolite 5144 and they say gap of .044. Does each plug have a different gap?
Thanks,
Christine

 

Gap them all the same. My stock plugs are supposed to be .054 as well. However, I installed Denso Iridiums and gapped them at .050 . I'm not sure if I would gap them that small, but I am not familiar with the Autolite 5144's. Where did you get the .044 gap # from? Was it for your vehicle specifically?

 

The 4.2 is weird like that...see, one side of the ignition fires on the positive side, the other side fires on the negative side. When the 4.2 first came out, Ford specified two different spark plugs for that engine, so you'd have different plugs on opposing cylinders. They've since updated the plug to where there's only one plug, and it'll work for either side of the ignition. I'd split hairs and lean towards .050. Make sure those Autolites are like the latest Motorcraft plugs, in that it doesn't matter where you install them, that they can fire on either side of the ignition.

 

Some more words of wisdom...

Use a torque wrench, I am not sure about the 03 torque spec. , but mine is 13 foot lbs. Harbor freight has them for like $9.00, not the greatest, but it will work.

Do not use antisieze, dry install only.

Take your time.

 

Ford used single vs double plats on one side only as a cost savings measure during manufacturing. Saved a few cents on every vehicle by using the singles where they would work adequately.

All replacement plugs have always been the same type - first double plats, then fine wires.

Haven't heard of the Autolite 5144... but if you're usng the APP5144 (duoble plat), you should be fine.

As far as the gap, follow the recommendation on your emissions decal under the hood regardless of what Autolite says to use.

Steve

 

Steve, they are the APP5144's. The .044 specs were from the Kragen site when I looked up my plugs so it was vehicle specific.
I do have a torque wrench. I asked for one for Valentine's day once because I was rebuilding my Miata motor. Then I got tools for Christmas. I'm wierd.

 

A girl with tools who changes her own plugs

 

Actually, English, that's a WOMAN with tools who changes her own plugs.

A *Girl* is a GUY who has no tools and is capable of only changing his own shorts.

But I do agree - that's just terrific to see. Bravo!

Getting back to plugs... try checking Denso's website - they have good install instructions. Note they mention different torque specs with and without anti-sieze. I favour the use of same, due to the dissimilar metals.

It's here: http://densoiridium.com/installationguide.php

Cheers
Vic

 

Tools for Christmas?? ,,,,98