MisFires - How long to log a code?

[07EddyB]

So I've noticed the Ex bogging at lower speeds while in overdrive with a little jumping action on the tach. Pretty much that same condition that led me to change the plugs 20K or so ago. That took care of it at the time. Back then, I didn't have access to the codes - now I do through the Torque app and a tablet. Just checked and no logged codes. Idle seems great - as long as I keep it up in the powerband it runs great. All of my coils are original so I've been waiting for them to fail based on the posts here - they don't seem to last long and I'm on borrowed time at 11 years old and 103K.
I know it takes a while to throw a CEL - but does it take a while to log a code on misfires? Or do I have a bigger problem?.
And BTW - the fuel filter was replaced a year or so ago so it isn't that.

 

[tripplec]

IMO if its misfiring a lot it should flag it maybe harder throttle with force the issue for you. If you are suspecting coils which seams to be the first most likely cause and have original coil. I might suggest getting at least 2 from Rock Auto. I looked for my son's ride thinking he should carry spares. They are pretty inexpensive ones which should be reliable if you read the oem info on them. Once you have a suspect cylinder or two you can swap out the coils.

Making notes on which ones you put them in and/or marking the coil (used one, where it also came out of) all to make the elimination process smooth. Masking tape on old coils can be written on etc. New coils with a blob of ladies nail polish on top or other more brilliant ideas.

 

[Explorer_PL]

EddyB
At 103 it's time for them
Get Motorcraft, nothing else, I tried Accel and it almost cost me a tranny.

I have gone through number of misfires, never set off the CEL light or stored a code.

After it got really bad, and when I punched it going up the hill with a trailer, I finally got the code.
Of course on a better reader it would show you the count of misfires if you have access to a better OBD reader.
Ford has a very high tolerance for that.

 

[tripplec]

I don't buy that only Motorcraft. They don't make their parts. Its subcontracted to some company to make their brand for them as 99% of the vehicle is a cumulation of offshore parts made for Ford in this case.

Summer when the heat is high under the hood is the hardest on electrical components and this is not that time. Any quality part will work in the winter and get to the problem. Once isolated he can buy a Motorcraft at 400% more if he wishes. I wouldn't, after all its a coil period.

 

[07EddyB]

I'm considering just ordering 8 and getting it over with. So I'd like to hear from people that have used cheap coils and how that's been going for them. Like tripplec, I know they don't build coils - I would love to know who their supplier is. There is a huge difference in price here.

 

[boominXplorer]

Pull out the last 2 coils on both sides and check for water. It loves to leak though the poorly designed cowl clips right onto the rear plugs.

 

[Bill MacLeod]

^^^^ What boomin said.

If there is any evidence of moisture or corrosion, smear some dielectric grease on the boot seal.

 

[07EddyB]

My Ex lives in a garage and I've never had the water problem. I've done plugs before and found no evidence of water in my rear wells. I know it's a known issue but I've never seen it on mine.

 

[boominXplorer]

All it takes is 1 good rain storm and a little time. I find the water leak very common, in almost every 06-08 truck I've tuned up.

Lay a few peices of computer paper on top of the cop's and intake and shut the hood. Then take a 5 gal bucket of water and dump it on the cowl or wash the truck. I'd be very suprised if you told me they stayed dry. It will leak right though the clips that hold the cowl down.

 

[MNgopher]

After having an '04 F150 with the 3V 5.4 and my '07 Explorer with the 3V 4.6, I've had more than enough fun chasing around misfires on these as the miles have added up. With that said, it is pretty easy to narrow down.

Using the Torque Pro app, run the test results (i can't remember if you have to add this in as a plug in or not, but if not, it shows up in the section where you can pick realtime results, graphing, etc...) , and wait for a bit as it takes it some time to get to the misfire results. When it gets there, it will report misfires by cylinder. Look for the cylinder that consistently throws misfires, and odds are you've found the culprit on the bad coil. That's worked for me in diagnosing 2 bad coils on the Explorer and 4 of them on my previous F150.

You can diagnose these long before a code will ever be thrown - it takes a lot of misfires before that happens.

On the Explorer, the thing that seemed to trigger more misfires than anything was heavy throttle applications. On the F150, it was light throttle application in 4th gear on the verge of needing to downshift. You can figure out what causes the bulk of them with some experimentation.

And last, I'll second the suggestion to use motorcraft only on the coils. Way too many reports of the others fixing the problem for a short term, only to fail again after 10-20 thousand miles. For me, if I am going to do the job, its going to be done right and I am happy to use aftermarket parts when they are better than OEM. This isn't a place where that seems to be the case.

Yes, the motorcraft parts are made for Ford by somebody. The deal is that Ford sets the parameters though - ie: the design life and what % of them are allowed to fail before that design life. An aftermarket manufacturer can set the design life at whatever they want, and allow the failure rate to be higher too.

I've gotten motorcraft coils from rock auto for around $45 a piece, and have gotten them around that price at Advance Auto when ordering online and picking up in the store on some of the % of store pickup deals. I only replace them as needed. On my F150, when I sold it at 193,000 miles, it had 2 of the original coils left. The 07 Explorer has had 2 replaced to date with over 132,000 miles.

 

[Explorer_PL]

MNgopher beat me on that, so let me just reiterate -

Coils and coils are not the same.....
The aftermarket sets are cheaper, but in some cases what you'd pay at a parts store for a set of non OEM is about the same as a set of Motorcrafts when you find a good deal online.
Few years ago I bought a set of yellow Accel coils for less than $ 200 IIRC, they fit perfectly, and the engine run perfectly smooth. But after few months (and I clock lots of miles daily), they were going bad one by one, and I started swapping the old good OEMs that I kept. At the end, I only had 2 yellow ones under the hood, and they threw a havoc in my transmission communication.
That only confirms what MNgoopher said: they all work, but the QC to be an OEM supplier is much tighter, if you want to stay in business for a big one, you better use the right metal for the coils and keep your standards high. A coil and coil can be 2 different things: the quality of wire matters, same as with the tools. A wrench is a wrench, but there is a reason why you pay more for certain brands.

But in the end, the choice is 100% yours.

 

[boominXplorer]

When in doubt always use Motorcraft coil but I feel Denso makes about 90% of the oem coils (I know for sure they make the 2v v8 and the 3.0 escape ones). Pic is of a Denso coil but if you look hard you can see the ford part number sharpied out under the sticker.

 

[thebrakeman]

Take it to an Autoparts store, and let them scan it. Better scanners can check for "Pending Codes". When I had some misfires causing CEL, I swapped 2 coils, reset the CEL, and drove it. Felt the misfire still, but no CEL. I used my ScanGage to check codes, and sure enough, the misfire was still at the same cylinder. Swapped these 2 spark plugs, and the Pending Code moved to the other cylinder. Put in new plug, and all was right with the world (all 8 plugs had been changed only 10,000 miles previously by the previous owner).

 

[MNgopher]

And if its the coil, and not the plug, and doesn't misfire often, it won't even set a pending code. It takes a lot of misfires before either a pending or actual code is set .

Per the Ford information on the misfire system, there are two thresholds that will set a pending or actual code. One is 1-2% of the time a misfire is detected per 1000 revolutions of the engine - or 10 misfires per 1000 revolutions. The other may allow up to 40% misfires before setting a code.You can feel way less than that - to the point that on a normal drive if I log more than 5 misfires on one cylinder it feels like the engine is running like junk... And that is 5 misfires over a 30 minute drive - the engine runs 60,000 revolutions in a run like that - with only 5 recorded misfires, when it takes 10 in 1000 to trigger the code.

If you are interested in the theory, there is a lot of information here:

https://www.motorcraftservice.com/freeresources/obd

 

[07EddyB]

MNgopher - thanks for the hint on the Torque app. I had downloaded the Ford pack some time ago and didn't realize it would count misfires real time. I've put the 8 cylinders on the dashboard and I'll start carrying my tablet with me on the road. Hopefully this will help me know where to start. I know the right front is cylinder 1 - are they odd on that side even on the other or do they count 1 2 3 4 on the right side?

Edit - Google tells me that 1 and 5 are out front. 1 right and 5 left.

 

[07EddyB]

Well, this is either good or bad news - not sure which. Monitored for misfires on my way to work today and nothing real time. Viewed the test results section and no misfires counted there either - even over the last 10 cycles. I did feel the issues though a few times while driving. Either Torque is lying to me or I'm using it wrong or I have another problem.

 

[07EddyB]

I continued to play with Torque Pro this week hoping to get an indication of which cylinder is the problem. I have monitored each cylinder as well as the total misfire count and never even gotten 1 to pop up. I have been looking at the test results and same thing - not a single misfire even during 10 drive cycles. Yet I feel a misfire.
So - I have another problem or bad data. Obviously, bad data is the easiest to diagnose at this point.
I pulled the power to the #2 coil and fired it up. I had no idea that engine would run that rough even at idle with one dead coil. As a friend used to say, shaking like a dog sh**ting peach seeds.
I got no misfires on individual cylinders for real time data - I got one misfire on total misfires on the test results side. I ran it for about five minutes - long enough to actually get a check engine light.
That doesn't seem right - I don't think I am getting reliable data here. I can see where the occasional misfire wouldn't be reported with my setup.
Off to Google I go.
Of course, you're welcome to tell me where I went wrong and save me some aggravation.

 

[07EddyB]

Hunting misfires has been a waste of time - I fear that it is, indeed, a transmission issue. I've noticed a vibration and noise sporadically over the last few weeks but I really got it last night. Running about 45 in top gear and overdrive it started again when I gave it a little gas. It literally feels and sounds like I'm on the highway rumble strip. I can make it start and stop at will now. From my research it seems pretty common and step one is to do a pan drop, filter and fluid change. If that doesn't work it's probably the OD solenoid.
Looks like I have some more research to do. I do know that they didn't make that job easy on this vehicle.

 

[07EddyB]

The new filter came last night - the fluid and the MityVac are out for delivery tonight. Hopefully I'll get to it this weekend along with the new cables and extension springs on the attached garage door that's been out of service all week. Own an Explorer and a house and your weekends are never boring.

 

[PotatoExplorer]

Hah, oh my this sounds like my Explorer problem. The new filter/trans fluid helped get rid of my rumble strip issue. Ive tried just about everything to get rid of the little tach blip/rpm surge and pretty much gave up. I feel a lot better now that I did