Ford 4.6 V8 spark plug question

A neighbor asked if I could do a tune up on his 2006 mountaineer with the 4.6 V8. It has a bit over 100k miles, and sounds like it has a misfire, but its not giving a CEL.

It looks like the plugs have never been touched, and IIRC, these plugs are known for getting stuck and broken.

Was this problem solved by 2006, and if not, what am I in for if I take on this job?

Also, it seems like the pickins are slim for replacement plugs for this application. Are motorcraft required? I only ask this because my normal parts source doesn't carry motorcraft, and none of my regular favorite brand plugs are available for this engine, just Champion and autolite.

I can't add much except to say that my brother just lost an engine this way. Tried to change the plugs himself, realized he had an issue and took it to the dealer. They "thought" that they got everything out and promptly destroyed the engine. He had it replaced and dumped his Expedition ASAP.
One less Ford customer in the world.

Be careful.

PS I don't for sure but I think his was a 2006 or newer.

Early models would pull the threads out of the head, later models the plug breaks off in the head. I don't recall the year that they changed, but I would assume yours is the later one because of the small selection of replacement plugs (long goofy looking plug that run around $12 each).

From a friend who is a ford tech, he will crack each plug about 1/4 turn, then fill each plug hole with PB blaster (or equivalent) and let it sit at least over night. On higher mileage ones he will repeat the process for several days before he attempts to get take them the rest of the way out.

I've read the trick with the funky long ones if you're in a hurry is to use an impact gun, the hammering breaks loose the carbon buildup or whatever gets them stuck in the first place. If you do break one, lisle makes a kit for extracting the ends iirc.

Actually this problem is only on the 5.4 due to there being less threads on the head to set the plugs in.

Mine were changed for the 1st time at 200K and there was no issue if done with care.

I have had 20 x 4.6 Crown Vic/Town Cars, never had a thread strip, did have one plug blow out, but it was able to be re-threaded and was not a recurring problem

I changed the plugs in my 4.6 mustang many times with no issues. I used proper torque specs for the new plugs during installation.

Aussie is correct, it's the 5.4 that I was thinking of with the plug problems. My mistake.

Its not 4.6 or 5.4, its 2 valve or 3 valve. The 2 valve engines strip the threads, the 3 valve engines break the plugs. If you don't feel like buying the Lisle plug removal tool, don't do the job. A 3/8 impact will generally get them all out, but no promises.

Champion makes a one piece plug, and a couple of other manufacturers have them now, too.

My 05 Mustang has the 3 valve heads with the break-apart plugs. I believe in Mustangs they didn't solve the issue until 07 but I'm not sure which heads they were using on mountaineers. There are a variety of one piece plugs available for the Mustang, the motorcraft plugs are not a requirement. You should be able to cross reference the part number for the mustang plug from the same year. If the Mountaineer is running the same factory replacement part number as the pony car, then the aftermarket plugs should work for it too. I've been running plugs from Brisk racing in a stock replacement heat range and have had no issues.

As far as replacing the glass plugs, take care. When I did mine at 70k mile I broke half of them. One lost bits into the cylinder that I vacuumed our using a shop vac adapted down to a fuel line hose. I used the toe from a pair of panty hose in one of the hose junctions to catch the bits and reassemble all the shards to make sure I got everything. Painstaking, but 30k miles later it's still running fine (so far.)

One bank of my plugs came out clean and fine - here's what I did: One WEEK before you do the work, Get the engine fairly warm, then pull the coil packs. Fill the plug well in the head with penetrating oil (PB Blaster, homemade, whatever.) Let the car sit unmolested for 24 hours. soak/vacuum all the excess oil out of the wells, put the coil packs on and drive it. The day before you are going to do the work, repeat the warm and fill. The next day clean it up enough to run the engine and get it good and warm. While it's still warm, start pulling plugs using the fastest 3/8" Impact gun you can get your hands on.

All of the plugs I did this way came out clean.

Bottom line - If it has the 3V heads, it probably has the breakaway plugs. If the truck were mine I'd be willing to attempt it. On a neighbors truck I probably would not - too much liability combined with too great a chance of breaking a plug. You don't want to be stuck buying the guy an engine.

Just in case there is some confusion as to which version of the 4.6 engine I'm talking about, its this one. (I don't know enough about these to be confused )

I used autolite plugs, they are cheap and work fine. Usually got 60K before they started showing increased fuel usage.

I never had a 4.6 strip a plug in probably 50 spark plug changes in the 20 cars over 10 years I used these cars for business.

Hint a shuffle in the power band off idle is always a bad plug wire, don't replace all 8, expensive, swap out a spare wire until the bad wire is located and drive. it

They do not have much power, duh.

All my experience is with 2 valve engines

Streetwiseguy wrote: Its not 4.6 or 5.4, its 2 valve or 3 valve. The 2 valve engines strip the threads, the 3 valve engines break the plugs. If you don't feel like buying the Lisle plug removal tool, don't do the job. A 3/8 impact will generally get them all out, but no promises. Champion makes a one piece plug, and a couple of other manufacturers have them now, too.

This, This and This.

<- had a 2v 4.6 plug blow out 30K after it was installed by a ford dealer.

Neighbor, 3v ford? That better be a damn good neighbor.

I'm dreading my 5.4 3-valve plugs. I've got the plugs and the Lisle tool already. I'm just waiting until spring so I can drive the Miata again in case I have some kind of epic failure.

If it is a 3v, water and ATF the motor before removing the plugs. That will/should remove the carbon buildup on the plug ends which is the problem on the plugs breaking in the first place IMO.

In reply to Ranger50: Please explain the water and ATF thing.

Remove the brake booster line, drop it into a bottle of a mixture of ATF and water while it's running. Manifold vacuum will suck up the mixture. The flash steaming of the water, and the detergents in the ATF will help loosen the carbon on the spark plugs. Otherwise known as the "seafoam" procedure.

Since nobody's posted a picture yet, here's what you're dealing with:

HappyAndy wrote: In reply to Ranger50: Please explain the water and ATF thing.

Use a 50/50 mix and pour in the intake with it running the water steam cleans the carbon and the detergents in the ATF help penetrate the carbon. Cheaper then seafoam.

Everything I've read say turn the plug after soaking under the coil pack as someone above said warm engine then leave the mix in the plug hole and turn plug 1/4 to 1/2 turn and let sit an hour or more to let the stuf work in the threads and top of carbon on the plug.

My 2V plugs did not look like those.

They were regular spark plugs

those are 3 valve plugs. Notive the mismatch between the engine pic above and the caption?. In the pic it clearly says it's a 3V, but the caption lists it as a 16 valve ( 2V x 8 cyl.)

HappyAndy wrote: A neighbor asked if I could do a tune up on his 2006 mountaineer with the 4.6 V8. It has a bit over 100k miles, and sounds like it has a misfire, but its not giving a CEL. It looks like the plugs have never been touched, and IIRC, these plugs are known for getting stuck and broken. Was this problem solved by 2006, and if not, what am I in for if I take on this job?

Is it a 3 valve or 2 valve engine? There is no "the 4.6". There are many 4.6s.

The 2 valve has the plugs that blow out, the 3 valve has the ones that get stuck.

Was just over on Speedtalk, apparently people have good luck 3v-wise with getting the engine to full operating temp and then burping the plugs out with a 3/8" impact gun on the lowest setting. And if they break, well, they were going to break anyway. You DO have the Lisle tool on-hand, right, along with the second easy-out mandrel that you cut down and modified for when the #4 plug won't come out with the as-produced mandrel.... right?

Just did plugs on a 2006 Corolla with 120k on it, 3 came easy, 4th was not moving. Backed it out 1/4 turn, PB Blaster, did the other plugs, and the 4th came out OK. Little antiseize on the threads during reassembly.

I would not touch one of those for all the money in the world. I still remember my neighbor asking me to help him change the plugs, little did I know they were prone to breaking into two pieces. That was my worst week in the last 10 years.

The plugs came out like the picture above. The car ended up at the dealership. Thankfully my neighbor was cool about it, I don't even know how much it ended up costing him.

To be pedantic, they don't break into two pieces, because they already are two pieces. Thus part of the problem.

Well,, at least Ford did solve the plugs blowing out problem.

Try the new CRC product before pulling the plug it claim to clean up miss fires and decarbon.

Would removing the plugs at every oil change keep them clean enough to prevent breaking?