Misfire update. ARRGGHH!!!

[jseabolt]

I installed new plugs yesterday. Compared to the new plugs, the electrods on the old ones looked worn at 114K miles. The gap had increased. So I was confident new plugs maybe what the doctor ordered.

After starting the engine, it seemed to idle OK. After a 10 mile test drive it seems the engine runs worse!! How could installing new plugs cause an engine to run worse?

Symtoms:

1) If I hold the throttle around 1500 rpms at idle, the misfire is felt.
2) If I hold the speed at 45 mph (most apparant at this speed), the misfire seems to be happen every 4 or 5 seconds.
3) When this happens I hear this rumbling sound as if I hit those hash marks carved into the edge of the road to warn me I am about the run off the road.
4) RPMS actually increase a bit when this misfire occurs (shouldn't that be the opposite?)
5) misfire doesn't seem to occur when the cruise control is on (weird).
6) Still the check engine light does not kick on. I have not connected my scan tool since to see if it's throwing a code.

Does any of this sound familiar?

So I installed new plugs. What's my next step? Buy a new coil and start with cylinder #1, test drive and if this misfire doesn't go away, move the coil to the next cylinder?

If I unplug the connector on each coil, and the RPMs do not drop on that cylinder would that tell me is that cylinder is misfiring?

Still not sure if this is a random misfire or a dead coil. Assuming this is ignition related.

One thing that scares me is on one of the plugs, the neck had some slight surface rust on it. That maybe nothing to worry about. I did not notice this on any of the other plugs. Based on the overflow tank I am not seeing any lose of coolant. As if I have a bad head gasket or a leaking intake manifold.

Any tips at troubleshooting this problem? I'm thinking about just taking it to a guy I trust who owns a shop and pay he to troubleshoot it. I normally like repairing my own vehicles but I don't know if I can do this with my 1980s era diagnostic tools. I could be spinning my wheels on this for days.

 

[Explorer_PL]

JS -

I would do exactly what you said, unhook each coil at the time to see if rms change. You may actually "block" the gas pedal to keep it at maybe 1500 rpm so it is more evident. Once you know what cylinder has an issue, it's either sparkplug or coil - new things may also be defective, check for cracks, maybe you overtighten one of them and it cracked.

In my case, I had similar issue for 2 reasons: one was water in the sparkplug well #8, that will kill the spark. On another time, I did not seat the coil boot with the spring on the plug properly.
I do not believe you have a big problem, just little of diagnostic and patience

 

[kam327]

Those symptoms (except #1) are just like the ones I took my Explorer to the dealer for (while it was under ext. warranty) and their diagnosis was a bad torque converter. I had the slight rpm surge every 4-5 seconds at around 45-50 mph, especially while going up a slight grade, for a while. Then I got the hash mark vibration once and took it right in a day or so later. All those symptoms went away after the torque converter replacement.

Although I've noticed the slight rpm surge is back. So either the replacement TC is starting to go bad or that was never the cause.

 

[scubastevesx]

just my 2 cents and story it may help i bought my ex from a well know dealer
in the deal i had them change my plugs among a few other things. i also had felt a slight stutter once in a whlile on my extended test drive figured it
plugs at 78,000 they could use to be changed. so they changed plugs gave a brand new free loaner. picked up the truck a few miles on the way home
it miss fired. got to the dealer they looked up the code sure enough
miss fire number 2. they replaced the plug. i picked the truck up again
miss fired on the way home came back dropped it got my third free loaner
they replaced the number 3 plug picked up the truck this time they asked to
do a extended test drive all is well now its been 3000 miles no other
problems so far im very happy with my ex.. so long story short plugs
do come bad from the factory. iv never installed a bad plug. so like you
thought it was some thing else. it still could be a bad or week coil

 

[jseabolt]

Despite preferring to do my own repairs I wimped out and took my Explorer to the dealership and told them what I've told you guys. I could be spinning my wheels with this problem for weeks.

The conclusion:

Check engine light finally kicked on, on the way to the dealership,

#2 spark plug was defective! First time I ever bought a bad sparkplug
Transmission fluid was low a dirty.

The dealership suggested a transmission service which included a new fliter, back flush and new fluid.

The tech called me and he said this torque converter shutter at 45 mph was normal but a transmission flush should cure the erradic shifting.

I did not notice anything wrong with the #2 spark plug. He said something about the electode.

Anyway I drove it home today, about 10 miles and it ran great. Never even felt a shudder.

As to if I was actually feeling a misfire to begin with or the transmission constantly shifting made it appear the engine was misfiring is still not known.

At least the dealership did not insist I needed a new torque converter off the bat or a new coil was great news despite a $450 repair. I've never heard of this dealership ripping anybody off anyway.

 

[swshawaii]

Good thing is you had a full tranny service done. Bad thing is if you scanned
for DTC's, it would have likely thrown a p0302 code pinpointing cylinder #2.

 

[Ornery]

There Ought To Be A Law!

$450 repair? Diagnose and replace one plug, and a routine transmission service?

"I've never heard of this dealership ripping anybody off anyway."

This forum exists to prevent this type of mugging. I feel like we let you down... BAD!

 

[jseabolt]

$450 repair? Diagnose and replace one plug, and a routine transmission service?

"I've never heard of this dealership ripping anybody off anyway."

This forum exists to prevent this type of mugging. I feel like we let you down... BAD!

Well yeah, $450 is not cheap. You can bet if your going to the dealership your not going to come out with a $50 repair.

When I say didn't get "ripped off" I meant at least they didn't tell me I needed a new torque conveter or transmission rebuild. But I know what you mean.

If this was my personal vehicle like my Subaru and it was in the middle of summer I would have spent more time on it since my Yugo is my summertime daily driver.

I needed my EX repaired pronto because this is the only thing my wife has to drive that is not a stick shift and I work 12 hour shifts and it would be next week before I could look at it again.

Speaking of getting mugged. Dad took his 98 Chevy Van to a guy to have the brakes repaired. One side was sticking. That was a $400+ repair.

I asked Dad why he didn't ask me to fix it because brakes are one of the most mundane repairs you can go on a vehicle like an oil change but because of my work schedule he didn't want to bother me. I noted he was retired and all he had to do was wait a few days until I was off.

Anyway they guy fixed one side but then the other side started sticking so I told him I'd install a new hose and caliper which would fix it.

My repair included a new hose and caliper and no labor cost him $40.

Rudy's repair included a new rotor, brake hose, caliper and pads and was $450
Why the first repair included a new rotor I don't know. Maybe it was sticking all the time and messed it up and because the other side was sticking then releasing 2 seconds later the DS rotor was not damaged.

I still don't see how he came up with a $450 brake job and only fixed one side.
I mean a new rotor, pads, rebuilt caliper and brake hose from Advance would have cost $150 at the most.

Of course most mechanics will insist on OEM parts because it's not their vehicle. Because they say discount part stores sell junk and they don't want someone to bring it back to them.

That's BS. I have used lots of parts from Advance and Autozone and have never had a problem. I did get a bad fuel pump that crapped out after 100 miles. I bet these guys use parts from discount autopart stores on their own vehicles.

Incidently these spark plugs in installed were Autolites so they could have just as well have come from the dealership. Of course in that case I could have taken it back to them and had them fix it for free.

 

[Ornery]

I've got at least two trustworthy mechanics and a third repair facility I trust. I really don't mind paying them a decent buck, because I want them to stay in business, and I usually just give them the miserable work I don't want to do myself. But, what dealers are charging is criminal. Even their wondrous "extended warranty" prices, with deductible, are ridiculous!

Only way I know to get even, is by keeping work out of their hands by posting here. I'm going to redouble my efforts to see they lose a LOT more work from here on out!

 

[jseabolt]

I've got at least two trustworthy mechanics and a third repair facility I trust. I really don't mind paying them a decent buck, because I want them to stay in business, and I usually just give them the miserable work I don't want to do myself. But, what dealers are charging is criminal. Even their wondrous "extended warranty" prices, with deductible, are ridiculous!

Only way I know to get even, is by keeping work out of their hands by posting here. I'm going to redouble my efforts to see they lose a LOT more work from here on out!

My way of getting even is to do the work myself. Unforunately advancements in technology is not always on my side. In the case of vehicles where you need a hook the vehicle up to a special computer to understand why it's going what it's doing. Unless I can do the same thing with my PC out in my garage or laptop.

I did call two independent shops. I knew the first guy but he said he had five cars to fix and he erased his Ford data from his computer and reloaded it with data for German cars since that is what his shop specalizes in. He recommended a former co-worker from the Ford dealership.

That guy said the washboard sound I was hearing every 5 seconds sounded as if the torque converter was going bad.

So I was a bit concerned as to what to do.

I'll need to investigate to see if there are any independent shops in my area that specalize in Fords before returning to the dealership.

My co-worker who took me to get my vehicle fixed said there was an oil change place up the street from where we live that would flush a transmission for $110. I'm not so sure I trust these places.

Maybe I should have done that first. Bummer I couldn't get the check engine light to kick on until I was on my way to the dealership.

Now my Trabbi is just the opposite:

http://s222.beta.photobucket.com/us...Trabant?&_suid=136228129702007437203516454336

No fuel pump
No water pump
No radiator
No oilpump
No camshaft
1 reed valve
carburator
2 coils and 2 sets of points but I have an electronic ignition kit for it

But puts out 9 times the pollutants of an V8 Explorer!

25/35 mpg but only 28 BHP and a top speed of 60 mph full throttle on flat land!

 

[Ornery]

Trabant?

One extreme to the other. I pretty much split the difference for the past 30 years. Full size, full frame, four door, V8 FoMoCo Luxobarges and Panthers. This Explorer is an extravagance, and as soon as my wife tires of it, I'll be trading for another Town Car. Never owned a new car in my life, and I'm spoiled by the cheap, easy repairs of the big Ford sedans.

Anyway, I'll be sure to share any cost saving tips I can about the Explorer. When I was researching the purchase, most useful links I found lead to this forum, so we're in the right place!

 

[Jaswitzer]

Replace them all

I had the same misfire problem with my 2006 Ford Explorer Eddie Bauer starting at 115,000 miles. I replaced the plugs at 90,000 miles and have systematically been changing coil packs. I finally broke down and just replaced the three remaining packs at the same time. Not cheap but the problem disappeared. Running good ever since. It seems as one coil pack goes bad it causes the others to weaken and they go bad one after another. Poor plug design and coil pack design on this model.

Good luck.

One other problem I was having was a hard shift between gears. Apparently there was a recall that I never was notified on. For $95 my local transmission shop got the download and fixed that problem as well.

 

[Mannymechanic]

I installed new plugs yesterday. Compared to the new plugs, the electrods on the old ones looked worn at 114K miles. The gap had increased. So I was confident new plugs maybe what the doctor ordered.

After starting the engine, it seemed to idle OK. After a 10 mile test drive it seems the engine runs worse!! How could installing new plugs cause an engine to run worse?

Symtoms:

1) If I hold the throttle around 1500 rpms at idle, the misfire is felt.
2) If I hold the speed at 45 mph (most apparant at this speed), the misfire seems to be happen every 4 or 5 seconds.
3) When this happens I hear this rumbling sound as if I hit those hash marks carved into the edge of the road to warn me I am about the run off the road.
4) RPMS actually increase a bit when this misfire occurs (shouldn't that be the opposite?)
5) misfire doesn't seem to occur when the cruise control is on (weird).
6) Still the check engine light does not kick on. I have not connected my scan tool since to see if it's throwing a code.

Does any of this sound familiar?

So I installed new plugs. What's my next step? Buy a new coil and start with cylinder #1, test drive and if this misfire doesn't go away, move the coil to the next cylinder?

If I unplug the connector on each coil, and the RPMs do not drop on that cylinder would that tell me is that cylinder is misfiring?

Still not sure if this is a random misfire or a dead coil. Assuming this is ignition related.

One thing that scares me is on one of the plugs, the neck had some slight surface rust on it. That maybe nothing to worry about. I did not notice this on any of the other plugs. Based on the overflow tank I am not seeing any lose of coolant. As if I have a bad head gasket or a leaking intake manifold.

Any tips at troubleshooting this problem? I'm thinking about just taking it to a guy I trust who owns a shop and pay he to troubleshoot it. I normally like repairing my own vehicles but I don't know if I can do this with my 1980s era diagnostic tools. I could be spinning my wheels on this for days.

Im literally having the same issue 2013 Explorer xlt, changed plugs, now cylinder one misfire, changed coil and still misses at 40, no engine light this time. Have you figured it out yet?

 

[Explorer_PL]

Manny -

I think you need to post it in the newer Explorers forum, this is for 06-10 models, different engines, different issues
But a misfire is a misfire no matter what engine it is. Check the wires going to the coil and injector on #1. Are you getting signal there ? If yes, then it may be valve issue, compression, and other things. Also, new parts may be defective as well.

 

[Trainmaster]

You need a code reader that tells you the number of missed on each cylinder. That will isolate the problem quicker and surer than pulling each plug and all that nonsense. It's a good investment.

After you know where the problem is, troubleshooting is pretty straight forward. Swap the plug and coil to another location and see what happens. Check that the connectors are firmly installed. Then you can try swapping the injector. If none of that works, do a compression test.

My bet is a bad plug, misplaced coil spring or a bad coil. Don't even think of using those $12 parts-store Chinese coils. You'll just inject more intermittent problems. Go with OEM and you'll save time, money and grief in the long run.

 

[ThunderbirdSport]

Holy 7 years dead thread revival, Batman!

LOL, yes, Trainmaster is spot on. Code reader will tell you exactly which cylinder(s) are misfiring. The misfire is pretty simple too. Coils or plugs.

If it's running rough and it's not a misfire you have bigger issues. Since it's a '13, that means EcoBoom....and I'm out of my element.

(topic hijack; before I bought my Expedition, I test drove a '12 or '13 Exploder Sport....had about 115K and man, I was NOT impressed. Gutless, sounded like **** was about to fall off, rode like a fwd car...of course, it IS a FWD car...yeah, no. I want my full frame, heavy, thirsty ole ***** SUVs.)
LOL. Yeah, I'll go pound sand now.

 

[Sgt.bustacap]

Holy 7 years dead thread revival, Batman!

LOL, yes, Trainmaster is spot on. Code reader will tell you exactly which cylinder(s) are misfiring. The misfire is pretty simple too. Coils or plugs.

If it's running rough and it's not a misfire you have bigger issues. Since it's a '13, that means EcoBoom....and I'm out of my element.

(topic hijack; before I bought my Expedition, I test drove a '12 or '13 Exploder Sport....had about 115K and man, I was NOT impressed. Gutless, sounded like **** was about to fall off, rode like a fwd car...of course, it IS a FWD car...yeah, no. I want my full frame, heavy, thirsty ole ***** SUVs.)
LOL. Yeah, I'll go pound sand now.

They definitely don't make em like they used too I rode my 95 right off the edge of a paved to unpaved road In the dark on accident ole girl took it like a good wife lol try doin that with low pro tires and these big ass rims stock now a days

 

[Trainmaster]

That's why I bought a 2010 V-8.

 

[94Eddie]

That's why I bought a 2010 V-8.

Same for me. I originally planned to buy a 5th gen Explorer. After doing some research on them I just couldn't get past the transverse mounted engine. Then seeing that the 5th gens are basically pavement queens with almost zero off road capability I bailed on buying one. The water pump issue with the V6 sealed this decision too. I don't know what I will buy once I am finished with my current Mountaineer but I am 99% sure it won't be a 5th or 6th gen Explorer. Also, I avoid small turbocharged engines like the plague so my options will be limited.

 

[Trainmaster]

I also have an Expedition and with Ford's move away from the V-8s I may be leaving Ford altogether. Or buying a pickup. We'll see...