Hello.

How difficult is it to change the plugs on a 1998 4.6 Litre? I've been told the plugs are very hard to get to, and that it's not a DIY job. Is this true? 1 more thing... If I change the plugs myself, are there any special considerations in regards to the "shooting spark plug" problem that the 5.4 and 4.6 engines are known to have? For example, is it easy to cross thread the plugs due to the low number of threads? What should the plugs be torqued to?

Thanks

 

Search these forums to get a better idea of what you're in for before you begin. If you decide to change them yourself be sure to blow compressed air around the plug before you remove it so the dirt pile there doesn't slide into the combustion chamber when the plug is removed. Stuff will act like sand paper on the cylinder walls. Not sure on the torque specs when installing new plugs.

If you decide not to change the plugs yourself take the truck to the dealer or a real mechanic, not some tire shop or quick lube. Because it takes some time to change the plugs on our trucks the price can be more than you think so ask before the work begins. Most specials for plug changes at those quicky lube joints don't apply to 4.6 Fords. If you know a few shops you trust call them and ask what they will charge to do the job.

Consider changing the plug wires at the same time.

 

I have a 97 4.6L and changed mine for the first time. Was very intimidated, but after reading some of the posts around this site, I decided to go for it. It is not impossible, but it was the most challenging set of plugs I've ever changed. I pulled the fuel rails off to get more room. Getting the boots to "pop" free is also trying at times, but all in all not too bad. Took about 3 hours to complete, I would recommend after you blow the plug holes out to spray a little wd-40 in the hole to help the plug break free. You can do this... don't be afraid. Also, get a 3 piece extension set (12", 6" and 4") and a swivel socket... worth every penny! Good luck!

 

Did you use anything special to get the boots to pop off? The seem especially hard to get off especially towards the firewall...

 

Don't use much WD-40, just a tiny tiny bit. Too much and you will wash all the sand and dirt and other nasty s**t right down into the cylinder when you pull the plug out.

 

it is not that hard. i changed the one;s on my sister's 97 150 with the 4.6. if you are going to replace the wires then you can use a pair of plyers to wiggle the back wires off. It is not as hard as it looks, takeing then out is the hard part.

 

Yes, a pair of leather gloves to protect my hands from pulling/prying with almost everything I had!

You'll see after you get the first one to pop...

 

Yes; good leather gloves are a great idea!

To ease getting the wire boots off the plug I slipped a long length of 1/8" nylon braided line (with a very small loop tied in it) under the wire using one of those long wire grab things used to pick up parts. Once your line is under the wire pull that line through and put the the other end of the line through the loop. Then cinch it up so you have a tight loop around the wire. Now pull (with your gloves on) and out it comes. Takes some jockeying around but it better than the other ways I've tried.

 

I took a real long zip tie (about 18") and removed the tab thatlocks it to the retaining end. Then I wrap the wire around the plug boot and thread the end through the retainer , snug it up and pull straight up. It works better than using a nylon cord because you don't need to use a pick up tool to threead the cord.

 

I let the air out of the front tires and tie the heater hoses out of the way with a piece of wire. The tire trick lowers the truck about 6 inches and makes number 4 a piece of cake to remove. I have spent an hour changing number 4. With the tires deflated I have changed number 4 in 10 minutes.

 

Aint it biatch - last spring I must have had my plugs in and out 10 times before I figured out the prob - The first time I changed plugs in my 5.4 - the new plugs were junk , had to do it twice - I'm a freakin pro now ...hahaa , yah , a pro by default lol ..duhhhh. Freakin Plugs!

 

Here's the instructions in case you don't have them lol -

I've replaced plugs on quite a few 5.4Ls now (the 4.6L with plug wires is similar) and once you've done a set they really are not as bad as they look. Contrary to what some people will say, you don't have to remove the fuel rails. The Coil On Plug (COP) assemblies will come out past the fuel rail. I take an old piece of seat foam and put it on top of the radiator support to the engine to allow me to lay on it without hurting my stomach. It makes the job way less painful.

Start by removing the cover over the throttle body (the black plastic cover that says "5.4" on it). There are three 10mm head bolts that hold it on. Next remove the air intake tube from the throttle body to the air filter housing. You loosen the hose clamps at either end of it, disconnect the connector on the AT (about half way up the air intake hose), the pull out the small hoses that go into the air intake tube near the throttle body. Next remove the brace from the power steering reservoir to thermostat housing. There are three 8mm or 5/16" head screws that hold it on. Now you should be able to see the COPs.

To remove the COPs you can use a 7mm or 9/32" wrench or nut driver or socket, extension and ratchet or all of the above. If you turn the fuel injectors to the side it will give you more room to work with the COPs. Unplug the connector on each COP by pressing the tab in and pulling on the connector. After you're done that just twist and pull the COPs out. A couple of the COPs on the driver's side and #4 on the passenger's side are a bit hard to get at but with some patience they will come out.

After you've removed the COPs take a blow gun and blow out the spark plug holes. Don't be surprised if there is rust and junk in them. Next you can actually remove the plugs. Use a combination of extensions, swivels (universal joints), sockets and ratchets to get at them. Whatever works best for you is good.

On the harder ones to get at I usually use a socket with a 4" extension, then a swivel, then a long extension, then the ratchet. The plugs are way down in the holes which is why I use the extension then the swivel. The swivel makes it easier to clear the firewall.

Set the gap on the new plugs to whatever it says on your emissions decal on the radiator support....usually .052-.056". Apply a small amount of anti-seize to the threads only on the spark plug. You can use a piece of vacuum hose or fuel hose over the end of the plug to get it started in the hole. Carefully start the plugs in their holes. If you can't get them most of the way in by hand with the hose take a look and see why not. Cross threaded plug threads are no fun! The plugs are to be tightened to 13 lb-ft. which is just hand tight with a short ratchet. Don't over tighten them! The threads in the aluminum heads have enough problems as it is. After that just put everything back together in reverse order. Apply some dielectric grease to the plug boots as well to help seal them. Seal off the plug chambers with more dielectric grease to repel water and moisture.

I've done enough of these that I can replace the plugs in approximately 45 minutes but don't be surprised if the first time you do it takes a few hours.


Goodluck!!

 

heres another from f150onlines home page -


https://www.f150online.com/forums/li...parkplugs.html

 

taking air out of the tires lol lol. now ive heard it all, it does make sense though, u can kill your back leaning over the engine

 

NO, no, no - I'm not the one that takes the air out of the tires - that takes to freakin long + it's very hard on the steel belts doing that. Anyways, by the time you start to let the air out off #2 , I would have both the tires/rims completely off and it lowered on a couple 1X12 blocks. You have to lean over no matter what unless you have some long a$$ arms lol.