What could be the cause for the coils on my truck to go bad, I just replaced the #4 and the #1 coils and now another one whent bad.

 

had a friend change #4 and he was told the a/c drips constantly onto the coil causeing it to be the most common. don't know if this holds true but is the only input i have on the subject hope that helps.

 

Are you sure it was the coil? I had a miss, no code. I changed all of the spark plugs and noticed a little electron leak on plugs #2 and #4. Th evidence was a 'spider web' looking dust arrangement on the boot. I cleaned the boots well, and reinstalled. So far, so good. NAPA sells the boots online @~$4 each.

Maybe this will help...

 

My truck (2000 F150 4.6, 48,000 miles) started to miss tonight , engine light come on and flashed, auto zone read it and it says P0307 #7 cylinder missfire.
Does that sound more like the coil or the plug?
it is the COP ignition

 

If you are getting the code and you have a serious misfire that goes along with it, the odds are 98% that the coil is bad, even if it puts out the proper resistance readings. I just replaced the #7 coil on my 5.4 with one from Auto Zone, and I took it back after I measured the resistance (primary and secondary) on all the coil packs, since it was sub standard. I picked up a new one from Advance Auto, tested the resistance before installing and have had no problems with it since then. The coil did appear to have a crack, but it was almost invisble. #7 seems to be one of the more common coils to go down on the 5.4. Also removing the fuel rail, and injectors greatly simplifies the replacement of the coil, and plugs.

 

Thanks, I will pick up a new coil this evening. Thats what I thought at 1st but there is the P0357 code for the coil circuit, so that kinda threw me off, I thought there may be a chance it could be the plugs.

 

I'm battling the same problem. my misfire is due to water leaking through the seal under the hood into the spark plug housing when it rains. if there is rust on your cop boot then you may having the same problem.

 

I finally got my truck to run good, I had to replace the O2 censor and the #1 coil. Thanks to every one who helped me!!!
thank you










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