Vehicle: 2003 F-150 supercab 4.6L 4x4 Sport manual tranny. 106k miles

Ok i've done a bunch of research and "think" i want to tackle this project. Here is what i think i know so far:

1. The 4.6 does NOT have the 2 piece plug that breaks off. Am i right?

2. On the 4.6 the 2 back plugs are tough to get at but should be doable. Anyone know exactly what extensions, swivels, u joints they used so i can go buy them?

3. So the main issue on the 4.6 is stripping the threads on the head as your coming out with the old plug? Any tips here? This would be terrible.

4. What's the torque spec on the plugs? I'd imagine this is very important because of the stripping and i hear these motors like to blow a plug out every once in awhile stripping the head.

5. I understand you should use a piece of hose to help start the new ones and get the old ones out. Also, blow out each plug compartment with air. Work on them while motor is cold. Spray creep on them the night before. I'm confused about using anti seize or not. Also, wouldn't the use of creep help cause the aforementioned plug blowout issue?

My fear is i'll strip the head or after i'm done 20k miles later a plug will blow. I am very mechanically inclined and will take my time and do it right but it makes me nervous. Truck has 106k on these plugs...its bound to start having problems soon and it'll no doubt be at the worst possible time...i'm all about preventative maintenance. I plan to go back with the exact plug that is in there now...they have been great.

Thanks in advance for any wisdom.

Brendan

 

1. Correct. That's a problem with the 3V engines.

2. I bought a set of these KD tools:



Permanently attached swivels so they don't come apart. Plus, they're magnetized and hold the plug perfectly so you don't need to use a rubber hose to start the new plug.

3. Stripping coming out isn't a problem, overtightening when installing is.

4. 13ft lbs. for the '03.

5. Dunno what Creep is, but in all honesty, you're less likely to spit a plug on the '03 MY because Ford increased the threads per plug hole in '03.

There were less threads in the '99 - '02 MY engines so the margin for error when replacing the plugs was very slim.

Just check your plugs occasionally and you should be fine.

Stewart

 

Thanks for the reply. Sounds like good news on the 2003 4.6. I'm still a little confused as to whether to use creep (pb blaster or wd40 or similar). What about anti seize?

 

* double post

 

Called ford and they said they use Kroil for the penetrating oil and there are no torque specs for the plugs ? He said their techs go hand tight then a bottom out with the wrench nice and easy then an 8th of a turn to no more than a quarter of a turn. I'd rather use a torque wrench with some kind of spec. I'm hearing 13 or 28 ft/lbs...

 

i changed them in my 4.6 a few times never had any stripping problems, sounds like the magnetic sockets are a great idea , plus alot of patients is a must spent around 2 hours each time

 

It's 13ft lbs.

My '99 Lightning is listed as 12 - 14ft lbs.

Stewart

 

I've done this several times. It takes me less than an hour. All you need is an 8mm 1/4 drive socket with all three lengths of extension, 1 inch, 3 inch, and 8 inch. Also you will need to get a standard sparkplug socket with the rubber inside, an 8 inch LOCKING extension. They are available from Craftsman but you may be able to find one at a local parts house. Just make sure that it is a locking one, meaning that you lock the socket on it rather than just being able to pull it off. This helps with preventing leaving the plug and socket in the bottom of the hole.
When you go to tighten the plug, you can use a torgue wrench to 13 ft. lbs. or you can do the run it down until it bottoms then just give it a bump. You can easily over torque them but it is not very crucial to have them torqued. JUST REMEMBER YOU ARE THREADING THEM INTO ALUMINUM NOT STEEL. They don't have to be super tight. They won't blow out.
All you need to do is unplug one coil at a time, remove it with the 8mm and whatever extension gives you enough room to reach the bolt without hindering your ratchet, blow out the hole, replace the plug and repeat in reverse.
I amazed one of my friends when I replaced the plugs in his truck. A guy we worked with said that he was trying to replace them in his truck and he and his son took 8 hours to do it. Can you believe it? 8 hours really? Well when I fixed his it took me about twenty minutes. The real trick is that if you don't have an overhead creeper just climb up on the radiator support and lay down on your stomach. Don't worry about hurting anything I weigh 275 and am 6'0" and have never torn anything up yet. Just look out for any small lines or sharp objects. They can cause unwanted headaches and pains. You usually can get the first four without climing on the truck but trust me it will make the last ones easy.
Sorry for the long post but I wanted to make sure that I included everything. Hope this helped.

 

Thanks for the long post. I'm a software developer and if I leave one semicolon out my stuff doesn't work so the details is what I'm looking for. Thanks again

 

Oh and the only horror stories that I have heard about plugs blowing out is with the V10's. Apparently Ford started using poor quality castings on these to save a few bucks and wound up having to replace a lot of them. So no fears there as long as you make sure to give them a little nudge once they bottom out with the ratchet.

 

Incorrect.

All modular engines from '97 to '02 were prone to spitting plugs. The 4.6L, the 5.4L, and the 6.8L were all susceptible to launching them into the underside of the hood.

The '03 MY heads were cast with more threads per plug hole, but even they have been know to launch a plug if the plugs weren't installed correctly.

The '03's, due to the more threads per hole, have a larger margin for error.

Stewart

 

Anyone out there change plugs in their V10 Econoline, yet. Wondering about access front and rear.

 

You might wanna post up in the Van Forum and see if they have some knowledge for you. 1968 - Present Full Size Vans - Ford Truck Enthusiasts Forums

Stewart

 

So far so good. Got the first 3 out on passenger side. About to try the 4th. Plugs don't look to bad for 106k miles. kroil is good stuff.

 

Done. Job went smooth. 6 and a half hours working pretty steady but not rushing. Thanks for the help!