06 Explorer 4.6L sputters in over-drive

[Stanggman50]

All...I'm new to this forum, but hoping someone can help out or may have had a similar issue and can share their experience.

I have a 2006 Explorer 4.6L with 84K miles. At around 74K miles it began stuttering when I was in over-drive going anywhere from 45 - 65 mph and usually up a slite incline. Initially I thought it was transmission related, but when I took it into the dealer the technician immediately thought it was a misfire. The car is under warranty (Ford extended warranty) through 105K miles. They replaced two coils and it ran fine for two days until the problem came back again.

I took it back to the dealer and they replaced two more coils on different cylinders. Again, it ran fine for two days and the problem resurfaced. I took it back this last time expecting to replace more coils but now they think it's due to the spark plugs and they want $800 to change them, and I'm not sure if that includes additional labor if they break any of them.

A few questions:

1) Is it possible that plugs with 84K miles could cause this? It seems plausable to me, but the plugs are rated to 100K miles.

2) $800 seems outragous to replace plugs. I'm fairly decent at basic auto repair. I've done a lot of work on older (87 - 93) mustangs, including freeze plugs, water pumps, alternators, rack & pinions. Is this something the average person could tackle? I've read up on the spark plug removal process; to take your time 1/4 turn at a time and use plenty of lubricant. I have all day this weekend to work on this, is this feasible?

3) Has anyone else had a similar issue and what resolved it?

Thanks again. Any input is appreciated.

-Mike

[Bill MacLeod]

Mike: Very possible that the plugs are worn and this is a job you can do.

Its best to have the Lisle tool on hand just in case.

Copy the Ford TSB and follow every step to the letter including using motorcraft carb spray, use a torque wrench set to specs for removal, application of anti-seize, etc.

I start with clean engine at about 80 to 100* temp. (Barely warm)
Crack plugs 1/8 to 1/4 turn.
Apply carb spray, let soak for 30 minutes or so. With torgue wrench set, go back and forth very slowly, until plug is removed. Don't force it, go slow. Use a little more carb spray if needed.
Use anti-seize on the barrel of the new plugs.

[rb1815]

i am having same problem, i changed two coils and all plugs. problem still persists. any ideas out here?

[granadojl]

Even though you swapped out those two coils, this problem still might be with a cylinder that is not triggering the CEL. Check all the ignition coils.

[Explorer_PL]

I am still on set of original coils at 141k miles, but on 3rd set of sparkplugs on my 06 v8. I had same symptoms, shaking, misfires. New plugs fixed that. They replaced the coils because that was easy.

[granadojl]

WOW... I wish I were on the same set of coils at 120k. I'm on my third set of coils. I check my plugs to ensure there is no damage each time I swap out a coil. I had to replace one plug due to a crap coil, but even then, I probably could have ran the engine a little bit longer. I'm the type of dude who fixes the EX as soon as I feel something weird with the engine, as I'm sure most of you all do as well.. hence this forum.

[bitkahuna]

wow, at 70k with my 06 explorer and worried about having the troubles at some point mentioned in this thread. so far, running like a champ. i wonder if it has anything to do with where the driving has been done (e.g., climate) and whether it's majority stop/go or highway.
i've kept the explorer because a) it's been reliable, and b) i expect it to continue to be so for a while.

not liking the sound of $800 plug replacement jobs!

[Divemaster191307]

I have 80,000+ on my 07 and getting the same symptoms. If I kick it out of OD, the problem goes away, btw. I'll tackle the spark plug change this weekend, weather permitting. Looking forward to a smoother running Ex!

[Explorer_PL]

That was my solution when it happened to me. I was 200 miles away from home when it got really bad, so I drove in 4 and somethimes 3rd gear with revs in 3-4k range for few hours.

[Divemaster191307]

The old girl is back to her old self again. Dropped a bunch of carburator cleaner Friday evening, and cranked the old plugs out this morning. #5 and #8 were the toughest. I had to take the CAI off for #1, but that was no big deal. I got a bit of a scare when I took it out for a test drive. I got a "Check Engine" light, with a Powertrain error and a Cylinder #1 Misfire. That was probably because of all the carb cleaner that drained in the cylinder. I reset the fault, drove about 45 miles and it never came back on. And the sputter is gone. Sweet!

[granadojl]

That's good to hear. Every time I my CEL comes on, I check the codes and fix the problem, then go for a drive cycle. If the problem has been resolved, the CEL will turn off by itself. Once, the CEL turns off, I check for any codes, and erase the existing codes ensuring everything is good to go. Just the way I work on my Beast.

[Essex4x4]

chiming in to this thread for sure. I had all 8 of my coil packs and plugs replaced due to a wonderfully horrific misfire that caused an EXTREME forward jolt. haha scared the crap out of me. All is well right now but I am still interested.

[06BlackXLT]

Hey All!
Just joined and can't believe I've found the right thread.....
I have a '77 IH Scout II and the forum is the only way to get good info.
I also have an '07 F-150 w/a leveling kit, 295/70r18s and a custom tuned SCT from Troyer Performance.
Bought my wife an '06 exporer w/the 4.6 V8 and 6 spd. At 65k, the truck started to shimmy in 6th under a slight load. Downshifted into 5th and it ran like a champ. Never set off a CEL though.
Thought it was the damn fancy 6 spd but the dealer checked it and it was fine. We have serviced it every 30k or so.
They changed all 8 plugs and swapped #7 and #8 coil packs. Ran good for a while but has been running crappy lately. We now have 123K hard "women driven" miles (sorry ladies) and the stuttering got to the point it happens all the time. A CEL has been on for several weeks.
Dealer pulled code P0307 (replace cyl 7 coil and plug) and P0420 (possible plugged cat). Dealer just put in #7 coil pack and a plug and I haven't done the cat yet. The truck has California Emissions on it. The truck drove for 1 F'in day then the stutter came back w/the check engine light. Haven't rechecked the codes.
Very dissapointed that the dealer only reads codes and doesn't diagnose anymore. I don't mind spending $ at the dealer but I expect it to be fixed when I pick it up and not to chase things spending good $ after bad.

Will a bad coil pack cause an overload of gas to enter the cats and make it not work properly?
My local exhaust guy said the truck doesn't have "banana in the tailpipe symptoms" and to drive it with high test to get it really hot to burn off any overloaded gas.
She will need an inspection sticker this month and I don't want to spend $1500 for cats I don't need or wont fix the shimmy problem.
I thought these plugs are good for 100k. Do you think I will have problems removing these second set of plugs after 60k and 2.5 years?
Need some input from you Explorer Gurus.
Thanks!

[06BlackXLT]

What are the Ford instructions for plug removal?
What do you guys use to read/reset codes?
Are we into metric sockets/hex keys, etc. on this truck?
What plugs would you guys recommend? Sourced from the dealer?

On my '77 IH, there is not one metric bolt, on my '92 Bronco there was still some standard sized stuff and on my '07 F-150 even more metric. Getting to the point where I can trade in my old sockets....
Thanks,
Mark

[Bill MacLeod]

Originally Posted by 06BlackXLT

What are the Ford instructions for plug removal?
What do you guys use to read/reset codes?
Are we into metric sockets/hex keys, etc. on this truck?
What plugs would you guys recommend? Sourced from the dealer?

On my '77 IH, there is not one metric bolt, on my '92 Bronco there was still some standard sized stuff and on my '07 F-150 even more metric. Getting to the point where I can trade in my old sockets....
Thanks,
Mark

Just my opinion:

Google the TSB and copy. Follow every step including using Motorcraft carb cleaner and using anti-seize. Need 9/16" plug socket for Motorcraft plugs.

I changed my plugs in Apr. 2011, didn't break any, but I sure was worried when the plugs screeched during removal.
Removed and inspected plugs in April of this year. Came out no problem, reapplied anti seize. (I'm just using standard a/s)
This will be yearly mainteneance for me.

And I apply silicone lube/grease to the coil boot and seal.

Have Lisle removal tool as back-up.

[06BlackXLT]

Thanks Bill,
Just downloaded the TSB and returned from the dealer w/the carb cleaner.
They were out of plugs!!! $22.99/ea.
Thanks for the socket size!
Will keep you guys posted...

[06BlackXLT]

So I found a local guy who has a Snap-On Solas hand held and got a code for a #8 misfire. I bought a set of Performance Distributors SOS coils ($300/8 coilpacks) and had them installed this past December. I swapped #8 SOS coil w/a random used stock coil pack I replace. I used conductive jelly to lube the boot and spring on the coil and went on SUPER EASY. I think too easy. Can that be a problem? I put the boot down as far as the mounting pad for the coil.

I just replaced #7 coil and plug. The dealer mentioned nothing about #8.
What can cause this "misfire" code?
My Dad thinks it is the "computer". The thing that controls the coils, injectors is messing up; the misfire codes are not the root cause of this. I also have a "possible clogged catalytic" code. My exhaust guy said the cats aren't clogged. W/the misfire, I think more unburnt fuel than the cat can handle is entering the cat and causing it to trip that code.
Any thoughts?

[Town]

Originally Posted by 06BlackXLT

So I found a local guy who has a Snap-On Solas hand held and got a code for a #8 misfire. I bought a set of Performance Distributors SOS coils ($300/8 coilpacks) and had them installed this past December. I swapped #8 SOS coil w/a random used stock coil pack I replace. I used conductive jelly to lube the boot and spring on the coil and went on SUPER EASY. I think too easy. Can that be a problem? I put the boot down as far as the mounting pad for the coil.

I just replaced #7 coil and plug. The dealer mentioned nothing about #8.
What can cause this "misfire" code?
My Dad thinks it is the "computer". The thing that controls the coils, injectors is messing up; the misfire codes are not the root cause of this. I also have a "possible clogged catalytic" code. My exhaust guy said the cats aren't clogged. W/the misfire, I think more unburnt fuel than the cat can handle is entering the cat and causing it to trip that code.
Any thoughts?

DTC codes are very important in any diagnosis so do you know the codes for the CAT problem. It is usually P0420 or P0430 or both which are efficiency issues related to too much oxygen detected in second O2 sensor. A blocked CAT usually results in very poor performance, but I don't know of an applicable code.

The misfire monitor defines a misfire as a cylinder that does not contribute its share to the engine rpm. A misfire can occur many times, and these are recorded, but you need a "scanner" to see the instances per cylinder. There is a threshold for the number of misfire instances to occur before the malfunction indicator light is commanded on. If the MIL is flashing then a serious misfire is occering that can endanger the engine and the CATs.

There are a very large number of possible causes for a misfire. The more common ones are: worn out plug, loose plug, failing COP, failing COP boot, bad electrical connection to the COP, moisture in the plug well, fuel injector problem, sticking intake or exhaust valve causing low compression, low compression due to a cylinder problem, etc.

Putting a conductive jelly on the wire COP connector to the plug is not normal practice. The boot connects easily to the plug because the boot fits snugly in the well to position the connector over the plug contact. If there is an excess of jelly at that point then you are in danger of grounding the spark to the plug well.

When the plugs and COPs are installed at the factory there is a small amount of dielectric grease applied at the spring connector to prevent corrosion. Dielectric grease is an insulator. Typically for a DIY plug replacement the dielectric grease is put over the plug metal connector and the ceramic body of the plug and the spring connector of the boot and a little inside the boot. Some put it on the inside of the plug well too but it attracts dust and dirt.

The Motorcraft plugs in Canada are $23 from the dealer, Autolites are $12 from a jobber and Champion are $18 from a jobber. The Champions are a one piece body and a 5/8" hex for the plug socket and work well. The Motorcraft needs a 9/16" hex socket but work well and are a two piece plug that is subject to separation requiring special tools to remove the remaining parts. I have no experience with the Autolites, since my son wanted nothing to do with 2 part plugs.

Good luck.

[wingley]

I have the same problem with my 2006 Explorer 4.0L with 171000k. I changed the plugs, plug wires, thermostat, O2 sensors and coil I also got the ECM reprogrammed and the CEL comes on after one trip to the store. Right now I am running with the CEL because I want to fix the problem before I change the CAT. My mechanic wants me to leave it with him to try to find the problem but I am a one vehicle family. I should also mention that there is no difference in gas mileage. I also ran it with seafoam in the gasoline and cleaned the TB with Seafoam. When I use the Chevron Premium Plus with seafoam, the problem went away but as soon as I put the second tank of regular gas, the problem came back. I think I will go back to the premium Plus and run with it until my next oil change or for a year.

[thebrakeman]

If you get a misfire, and a code reader that gives you the cylinder number, the first thing you should do is swap that coil with another (good) coil on another cylinder. Takes 5 minutes and could avoid messing with the plugs unnecessarily. Reset the code reader and go for a drive until it throws another code. If it moved to the other cylinder, you know it's the coil. If it's stays with the same cylinder, THEN pull the plug.

I did this and ended up change just that plug, since the previous owner had change the plugs not long before I bought. Just got a bad plug I guess. Haven't had a problem since.