Still having problems with 07 Explorer XLT

[HollyTautz]

The last time I posted, everyone was a great help. Unfortunately, I am still having problems with my poor Matilda.

Approximately a year and a half ago, I was sitting at a light when she shuddered horribly and didn't want to take off when the light changed. I pulled over into a big truck repair place (closest available) and they didn't see anything. But Matilda began hesitating/stumbling/jerking sometimes between 45-50 and sometimes at 65-70 especially when going up hill or in heavy stop and go traffic. It happened even when using cruise control.

I have had the coil pack, plugs, and wires changed last year at this time. I have had the transmission fluid changed and there was no metal in the filter. I have had the fuel filter changed. As I have had spare money I have tried different things to fix the problem with no success as there were no CEL codes. Within the last 3 months I would occasionally get a P0302 code. The repair shop said it was an old code that keeps popping up. I don't exactly believe that and am not going back there after that attempt to not deal with the problem and suggesting I need a new transmission even though I don't have any signs of the trans going bad but I could be unaware of those as well.

Now I have a rough idle upon cold start which will occasionally trigger the P0302 code. I have also noticed the #2 spark plug wire seems rather loose compared to the others on the coil pack. I had hubby pull it off while the engine was running and there was no change in RPMs but doing so with the other wires caused a drop in RPMs. And yes, I know it can be dangerous and not the smartest thing to do but I am at the end of my rope.

I am seriously considering replacing the coil pack, plugs and wires with Motorcraft products and I am going to do it myself with some help from a friend.

If anyone has been down this road and has advice or answers I would appreciate it. I hate not being able to drive Matilda long distances because I am afraid that we won't make it home. I don't want to get rid of her and my son really wants her when I am ready for something newer. She has about 155k miles on her and when she's having a good day, she runs and drives great. Body is in good shape and so is the interior. I really want to enjoy Matilda again ... please help!

 

[Rcflyer330]

have you checked the #2 spark plug it is possible the it is bad even being fairly new. with the wire can you explain what you mean by loose? is it the clips or is the pin that connects to the coil pack not tight? also the wire could have been bad from the factory.

 

[steve6534]

I would use a spark plug external to the head and check for spark. If that's good I would suspect the injector for that cylinder.

 

[HollyTautz]

have you checked the #2 spark plug it is possible the it is bad even being fairly new. with the wire can you explain what you mean by loose? is it the clips or is the pin that connects to the coil pack not tight? also the wire could have been bad from the factory.

The connection to the coil pack pulls off with almost no effort. You don't even have to really press the little clips. It also seems "wobbly" for lack of a better term. I haven't checked the plug yet because I don't have the tools here. When the coil pack, plugs and wires were done last year, it took extra time because they had to send for another coil pack saying that the one they had was defective. I am wondering if they were using the cheapest and worst made parts to keep the prices low.

My husband reminded me that #4 wire connection to the coil pack was similar in being loose as well. Not quite as bad but still easier to pull off than the others.

 

[HollyTautz]

I would use a spark plug external to the head and check for spark. If that's good I would suspect the injector for that cylinder.

Would you please give me a little more detail as to what you mean? I don't understand how to do this.

 

[steve6534]

This would just involve using an additional spark plug (or a spark tester preferably like https://www.amazon.com/Thexton-THE404-Spark-Tester/dp/B0002STSBM this) and connecting the plug wire for that cylinder to it. Then start the engine and check for spark. This will verify if the coil and wire are working good.

 

[Joey Threesticks]

I have had a few coil packs that were bad out of the box on my V8 explorer.

Try swapping another one of the known working ones on your problem cylinder and see if the problem follows the pack. Additionally, check the
plastic connectors that connect your wiring harness to the coil pack- they often corrode or get a carbon build-up that keeps them from operating properly- and they sometimes break too.

Another oddball Ford issue I had with mine- during the rainy season, rainwater would get past the cowl seal by the windshield and water would get into the engine
bay. Since the plug wells are recessed on my engine, water would pool there and seep past the plug boots, causing random misfires. This could also be felt as
a "hesitation" from a stop. During a long drive, the engine heat would evaporate the water in the wells and she'd run fine again.
>>I discovered this issue while pulling my plug boots, I had a white, chalky residue in my plug wells that was causing an arcing condition. Blew that out with some
canned air and was good to go.

Hope that helps! Think you're headed int he right direction.

 

[SteveOReno]

I have a rough idle and random misfire engine code P0306. Mine is cylinder 6 and yours is cylinder 2. So we may have similar problems. I replaced the plugs, wires, coil pack, crankshaft pos. sens., and fuel injectors. Nothing helped. Replacing the coil pack is very easy so you might try that just for fun (note that the V8 has coils on plugs which is totally different from the V6).
My latest theory is sludge on a valve component because another guy said he had a similar problem which was fixed by new valve components. So I may try seafoam in the oil right before my next oil change.
In the mean time, I have discovered that disconnecting the battery for a while (usually overnight) not only resets the PCM and clears the engine code, but it also fixes the rough idle, although it comes back after a few hours of driving. The computer (PCM) has a "limp mode" that it goes into after a certain number of misfires which causes a rough idle. In my case the problem cannot be too serious because the engine runs great at high rpms (when I rev it up).

 

[HollyTautz]

You guys are the best! I don't have a garage so the weather hasn't been conducive to me working on it and with trying to get my karate school open and running, time has been limited to go to my ex-husband's and use his garage.

I did take Matilda for a good long ride last night as I had to go training 20 miles away. She did awesome all the way to training, then from there to my ex's to drop some papers off he asked me to print for him so that was another 10 miles, then on the way home the jerking started between 45-50. It was raining off and on and trying go up this one big hill was really annoying as she bucked like a Mississippi mule! She smoothed out again after a while as that's another 20 miles home. I did notice the RPMs this time and during the jerking/bucking they were jumping between 2 and 3. When that happens if I hit the gas and get past that speed she'll settle down. I did have a little rough idle at the stop lights too last night.

Took her out running errands today and she was fine. We'll be heading out tonight to do some things and we'll see how she is. I am going to change out the coil pack, the wires and plugs because I do believe they are substandard. What is this sea foam that I've been reading about here? Can I get that at Auto Zone? Where does it go in at? I'm heading there tonight because I need new wipers and I need to get the oil for my K&N filter which needs cleaning. Tomorrow is supposed to be very good weather here so I'll be spending some time under the hood.

 

[SteveOReno]

I don't know how hard a Mississippi mule bucks, but the jerking may be a transmission problem. Unless your check engine light is flashing, which indicates a serious misfire, an occasional misfire should not kick or buck much. You should change your transmission fluid if it hasn't been done recently. That requires a special nozzle adapter and a hand pump if you do it yourself.
Seafoam is a solvent that can be added to gas or oil to clean your engine. Sometimes it helps, sometimes it doesn't. When you add it to your oil you should change the oil after giving it a few days to work.

 

[HollyTautz]

I added the Sea Foam yesterday and took Matilda for a nice long ride. She did much better or at least it seems that way. Didn't even run into the hesitation and bucking while going up a steep hill. I did have a small hesitation today while on the road but nothing like what I've been experiencing. Possibly a very dirty injector or two? I am also wondering about the Torque Converter too since I've been seeing a lot about that lately.

 

[zerodevil]

before you go too crazy, i have something free for you to try. Resetting the learned adaptive memory and fuel trims. unhook the positive and negative leads from the battery and leave them touching each other in the engine bay for 20 - 30 minutes, you can also attach them to each other with a set of electrical clips if you have some. This will not harm anything, just make sure you have the connectors away from the posts on the battery, and to drive the vehicle reasonably for the next few hours after the procedure. On my 2003 V8 on a partially failed coil for a few weeks. long enough for the vehicle to mess with the long term fuel trim, and prevent the vehicle from running right after replacing the coils with new units. I also had a fun experience with my new 2008 explorer V8 when I replaced the spark plugs, where i received two DOA plugs right out of the box.

 

[SteveOReno]

You can short the positive and negative together, after disconnecting one from the battery, or you can skip the shorting and just leave it disconnected overnight. The computer has a capacitor which takes a while to discharge. Turning on a non-computer controlled light will also discharge the capacitor, like your brake lights.
I can confirm that reseting the parameters, i.e. fuel trim etc., by disconnecting the battery will make your engine run better if you have a random, intermittent, problem like a misfire. Once the computer senses a problem it tries to correct it or compensate for it but then it does not seem to recover from the problem cleanly.
It is probably not your transmission because that would be a more consistent problem (I see now that you did change your trans fluid, which is always a good thing with this vehicle).
I am curious as to how often you are getting the misfire engine code, assuming you have a code reader.