Gravyhound

It is with the 4.2 v6, it is an auto trans. Im having problems with the ignition coil, it keeps going bad and I change it and than it runs great for a min. of 6 or 7000 miles and than it will have another missfire and same thing the coil again. I have changed it 4 times in 25,000 miles. here are the facts- I got the truck with 92,087 with in 300 it had a slight missfire, getting bad gas mileage so I figured with 92k mi. it was time for new plugs and wires (the originals) so i changed them, bosch plug wires and radium spark plugs that it calls for and that fixed the problem as I thaught it would and about 3 monthes later the first and original coil went bad. It does not go out completely its 1 or 2 terminals of the coil goes bad. If anyone has any idea I would apperciate it. thx kevin

Good old Bill

As I have never had a coil go bad on my 02, 4.2L with 226K and you are on your fourth or fifth, I am very skeptical. What do you mean its always 1 or 2 terminals? What missfire code are you getting? The processor, ECM, PCM or what ever you choose to call it is the last thing in the circuit, meaning it grounds the primary to induce high voltage in the secondary. Suggest looking into the circuitry further.

Gravyhound

I would call the 6 ports on the coil terminals, when i said 1 or 2 terminals go bad that would mean it would have 1 or 2 cylinders not firing. I dont remember the code but it was like a 304 or something like that but it would say #4 or #6 cyl. missfire and I thought 1 time it said random cyl. missfire. I am by no means a mechanic, but when it has a missfire after I just changed the plugs and wires 3 monthes prior it does not take a rocket scientist to suspect the coil. I changed the coil and it fixed the missfire (runs great) and than about every 8000 mi. the missfire comes back, change the coil and its good for another 8000 mi. or so, are you skeptial be cause it does not make sence to you or what? the definition of skeptical is 1. not easily convinced; or having doubts or reservations 2. relating to the theory that certain knowledge is impossible. The fact is that the coil keeps going bad eather because it is the cheep o'reillys house brand or something is making it go bad. Its a mystery!

Gravyhound

O by the way it is 4 times in 32000 not 25000

Good old Bill

It seems that I have offended you. That was by no means intentional, as a mechanic (now retired) for over 50 years, yeah, either the parts store is selling **** parts or perhaps the whole repair procedure is in question. I am leaning toward the later. I am not stomping on you at all, it just seems very strange that coils keep going bad. The question is what is causing them to go bad or at least, spitting up this code?

I mentioned about looking into the system deeper, codes printed do not represent a failed part. They alert us to a quirk in the system that is out of tolerance during a drive cycle.

The small wires connected to the coil, not the plug wires, are they making good contact (no discoloration, corrosion, proper contact), things of this nature could create a code?

I personally don't like parts stores, I prefer going to Ford for all my needs, unfortunately, with my older vehicles, (newest being my 02, 4.2L), this always can't be done. Check into the system farther, something will show up.

fleetnuts

I had a slight misfire with my coil, but no codes or lights. Couldn't figure it out, so I took it to the dealer and they said the coil wasn't producing quite enough voltage just slightly off to cause a slight misfire but no code. This is my second coil, first was went out about 3 months after I bought it brand new off the lot, first one was covered. Then the second one went out 3 years later, June 2011, it cost me $300 to have ford replace the coil and they cleaned my whole engine bay.

Gravyhound

Not at all bill, Im not sure what you mean by the whole repair procedure is in question but I have checked the little harness that plugs in on the side of the coil and they look good and clean and every time the eng starts missfiring the first thing I do is check all connetions, so far My money is on the cheep o'reilly parts, being made in china by the cheepest vender. I dont know what else to check but being that the cheep coil does have so 1 year warranty so it does not cost me money each time it happens and it only takes 5 min. to change so I guess when the 1 year warranty is up Ill try a motorcraft coil and see if it last longer.

papa tiger

Check voltage to coil with key on, if coil stays hot the ECU is not turning it off and on, reason it burns is it is on all the time.

transmaster

Papa Tiger has it; this is a PCM problem you will throw coil after coil at it and they will all fail from overheating.

Gravyhound

Great suggestion ill check asap