Solved How to change SPARK PLUGS on a 4.6L V-8

[SyberTiger]

As I understand it the maintenance schedule calls for changing out the spark plugs on this engine every 100K miles. I have 99K+ miles so I guess I'll change them out. I have several questions for those of you in the know on this subject. First let me state what I believe I've learned so far. Correct me please if any of this is wrong.

A. Use Motorcraft plugs. They perform the best in this engine
B. Torque plugs to 13 ft-lbs (156 in-lbs)
C. Use dielectric grease in coil boots
D. Torque coil pack to 4 ft-lbs (48 in-lbs)
E. Do not use anti-seize grease on plugs (it is not necessary)
F. Moving fuel rail is not necessary (use universal joint and 6" extension)
G. Use air pressure to blow dirt away from plug holes before removing plugs

Okay, here are my questions:

1. How do you remove the coil packs? What tools are needed?
2. What gap should the new plugs be set to?
3. Are all the plugs easily accessible without being a contortionist?
4. Is there anything else that needs to be moved out of the way?
5. How long did it take you to change your plugs on the 4.6L engine?

Can someone please expand on this process? What am I missing?

 

[FourXFred]

Answers
1- use a 7mm socket to remove bolts holding on coil packs. Then simply pull up on the packs and they will come off the plugs fairly easily.
2- I dunno. I use bosch +4's and they come pre gapped.
3- It looks scarier than it is. I can do them in about 40 minutes now that i have done them a few times. I found a six inch extension, along with a 10 inch extension with a universal in between worked well, just for some extra length on the rear ones.
4- I dont remember what the factory air intake looks like, but i know i have to remove my K&N one to do my plugs
5- First time i did it it took me over an hour, now like i said since i've done it a few times its about 30-40 minutes.

 

[SyberTiger]

I should add that the spark plug gap should be set to 0.054".

 

[wagoner2]

You have the basics, I did mine last weekend. Gapped @ .055, last two on the passenger side are the most difficult so start with those. Take your time and you will push right through it.

 

[SyberTiger]

Thanks guys.

BTW, I did go ahead and use anti-seize grease on the threads.

 

[SyberTiger]

This is what the spark plugs looked like on my 2002 V-8 after 100,000 miles. They don't look so bad. From some of the descriptions from others on this forum I was thinking all I'd find was insulator and no electrodes.

 

[EasyRhino]

Remember to remove the old ones when the engine is cold only. Don't want to bugger up the threads in the aluminum heads.

 

[alexk]

Where exactly are they located? I was looking under the hood today and couldnt find them at all.

 

[eXcali]

Where exactly are they located? I was looking under the hood today and couldnt find them at all.

The spark plugs? Track the wires from your coil pack and they will lead you straight to each plug.

 

[Curtis]

The spark plugs? Track the wires from your coil pack and they will lead you straight to each plug.

its not that easy... the 4.6 in the explorers dont have plug wires.
Since the coil packs are on top of each plug there's no need for a wire.

 

[SyberTiger]

Where exactly are they located? I was looking under the hood today and couldnt find them at all.

Step #1 Open the hood.
Step #2 Take the noise insulation cover sitting over the throttle body off.
Step #3 Then look.

The job itself is rather easy. It took me 2.5 hours and I was going REAL slow and goofing off. No sweat shed no letting of blood. Probably the first time in my life I've changed plugs in a car and didn't bust my knuckles somewhere. It took me a long time because I spent a lot of time blowing compressed air to blow the sand off the engine and spark plug area before removing the plugs. My little compressor was only good for two or three shots before I had to wait 5 minutes for the tank to refill with air.

 

[1_v8_merc]

Since it's an overhead cam engine, the plugs are above right?
I found 8 plastic cap things right near the fuel rail that all have wires attached to them, they looked like they connect into the cylinder head or something.

I dunno, i only looked real quick.


I've always used Autolites on Fords, and was told by tons of people to NEVER use Bosch plugs on fords, they tend to have problems....i dont know why, but i know a guy who installed Bosch plugs in his Ford Ranger, and apparently they caused the engine to mis-fire severely or something and completely destroyed his engine. The dude was PIIIIISSSEEDDD and i think he was attempting to sue over it........yea....

I always use Platinum or Double Plats, double plats are usually for engines with higher octane....from what im told, and allow you to go longer without changing the plugs next time around.
(i installed them on my mustang, no problems)

And regular plats are the basic good ones for most engines.

Not sure about copper plugs, i hear they are good....take it for what it's worth.

 

[02MANNY!]

Ok guys, I'm doing the same thing on my 02 Eddie and I can't see where my plugs are? I can see what looks like the connectors/fuel injectors but I can't really see where the boots and plugs are...a picture any one!
Also, do you all recommend changing the O2 sensor and PCV if I have over 94K miles? How hard will this be?
Thanks
Manny

 

[02MANNY!]

Ok, you can call a dumb a$$ What I thought was part of the fuel injector is actually the coil. I guess it's the beginner on me...????!!! Now I can see why they recommend removing the fuel rail and the air to clean the spark plug cavity!! Thanks for the help. I will go and change my spark plugs (I bought NGKs) to the motorcraft and change them out tomorrow, as well as the fuel filter.
I'm still looking to see where the O2 and PCV are located and make a decision if I will change them out as well. My X runs good but I'm in the process of doing a full tune up.

 

[Curtis]

Ok, you can call a dumb a$$ What I thought was part of the fuel injector is actually the coil. I guess it's the beginner on me...????!!! Now I can see why they recommend removing the fuel rail and the air to clean the spark plug cavity!! Thanks for the help. I will go and change my spark plugs (I bought NGKs) to the motorcraft and change them out tomorrow, as well as the fuel filter.
I'm still looking to see where the O2 and PCV are located and make a decision if I will change them out as well. My X runs good but I'm in the process of doing a full tune up.

No question is a dumb question.. for every person that will ask, there are 100 more wondering the same thing that wont ask. I have not done mine yet but plan to. Let us know how it goes and what you had to remove to change them.

 

[SyberTiger]

Ok, you can call a dumb a$$ What I thought was part of the fuel injector is actually the coil. I guess it's the beginner on me...????!!! Now I can see why they recommend removing the fuel rail and the air to clean the spark plug cavity!! Thanks for the help. I will go and change my spark plugs (I bought NGKs) to the motorcraft and change them out tomorrow, as well as the fuel filter.
I'm still looking to see where the O2 and PCV are located and make a decision if I will change them out as well. My X runs good but I'm in the process of doing a full tune up.

On my 2002 Limited there was absolutely no reason to move or even fool with the fuel rail. At first glance it might look like it is in the way but it really isn't. Just work around it. In addition, I never needed a universal socket. I used a 6 inch extension and another 4 inch extension in one or two places. You will, however, need to unplug several vacuum lines, the throttle body air intake hose, and a couple of electrical plugs that are in the way. It takes less than 10 minutes to do all of that. Lastly, when you get the coil packs unbolted you are going to find the rubber boots on the bottom of the coil packs are VERY long (guessing 4 inches) and reach way down into a spark plug well on top of the engine's aluminum head. Basically, when you pull out the rubber boot you'll be looking down in a hole the length of the rubber boot. At the bottom of the hole you'll see the spark plug down there. That is one reason why you need 6 and 4 inch extensions. You can't put your finger in the spark plug well and touch the top of the spark plugs. If you are used to the old spark plug set up on older cars with plug wires and protruding spark plugs you're gonna say "WTH!?". It is pretty easy though and easier than first glance. Don't panic, it's an easy job.

 

[1_v8_merc]

Yea i just went to check my spark plugs.
Got a question....

Has anyone had trouble removing their spark plugs?

I've only got 35k on my 2004 v8.

And this plug just wont ####ing come off.....should i break out a torque wrench?

I was reading over on the mustang forum, and those guys were saying they routinely need 25-40 ft lbs of torque just to break the plugs loose!

 

[SyberTiger]

I'm not sure how much force I used to take mine out but it wasn't bad and not to the point where I started to get concerned. Guess I lucked out. Anyhow, shortly someone is gonna come along and recommend you squirt some PB Blaster or equivalent down around your spark plug and drive it for a day or two. Be careful about using too much force on that aluminum head.

 

[alexk]

Thanks, I will check there later today.

 

[1_v8_merc]

I'm not sure how much force I used to take mine out but it wasn't bad and not to the point where I started to get concerned. Guess I lucked out. Anyhow, shortly someone is gonna come along and recommend you squirt some PB Blaster or equivalent down around your spark plug and drive it for a day or two. Be careful about using too much force on that aluminum head.

Haha, nevermind i got her loose. Thanks though!

The socket i was using didn't have the rubber o-ring in it, so i got concerned.
Eventually i found a socket with one, although it was in 1/2 inch size,lol.

I ended up using a small breaker bar socket wrench tool,.....that did the trick!

The spark plug i tested was all white around the contacts....thats good right?


Oh yea, if anyone pulls the spark plugs themselves, DEFINATELY have an air compressor on hand!!!
(or some compressed can-air found in computer stores)

Dirt WILL be falling all over the place in there most likely.