Testing Ignition Coil, Misfires

[lincoln4life]

2000 Lincoln LS with the infamous oil on #8 plug. (I know I need to replace the gasket). I've lived with just changing the plug every year and having my friend clear the PCM when the light would come on. Finally I'm here. I checked the resistance of each coil with a multimeter and each read .8 none of them read O.L. or had a significant reading. 1. Is this the proper way of testing for a faulty coil? Spark Plugs are new. Injectors are not plugged. He cleared the codes on the PCM. Car was like new again. EXCEPT..the wife stole the car for an emergency (she's a nurse) before I could tighten the plugs back down with the 8mm screws. She came back and it was misfiring and two of the coils were sticking pretty far out of the block. My friend said he couldnt test for misfires until there was an engine light or a code. 2. Anyone think the PCM is fried? Im rambling. 3. Where can I get a decent price for OEM motorcraft coils? Someone just laugh at me already lol. Thanks

[joegr]

A resistance check isn't going to tell you anything useful about these coils. The normal failure mode is internal breakdown of the high voltage insulation. To test for that, you need to do a stress test and scope it.

http://ww2.justanswer.com/uploads/s4...sb05-22-08.pdf

Assuming that you don't have the equipment to do this testing, it would be cheaper (and better) for you to throw all the coils away and buy new ones.

[lincoln4life]

Aight well. Im goin to change all the coils back to OEM. (freakin Autozone $70 buck ones won't allow me to put the coil covers back on). So I can eliminate the water rusting the plugs and boots when I power wash under the car and during harsh rain. Also Im goin to change the valve cover gasket finally. I attempted to just put RTV around that lonely leaking spark plug hole years ago, but that didnt work. JUST got the pink ticket on this thing two months ago. Im confident this will fix it. Ill come back with the results next weekend.

[lincoln4life]

Took 7 hours, but valve cover gaskets replaced and coils. NAPA gave me a military discount got 8 coils for 295 and both gaskets with orings for 80. (couldnt wait for orders online) During the swap I pulled the oil dipstick all the way out to replace the o-ring. TWO rocks from under the dirty engine fell in the dipstick hole!!! LMAO. I grabbed a vacuum and sucked them out. What Luck. Im sure more debris fell in that LIL ITTY BITTY hole so oil change or oil pump maybe next on the list. Oh, and the misfire has ceased.

[2002ls007]

Test individual coils by using a inline spark plug spark tester. Just plug it onto you coil, and run the engine...if the coil is bad you won't see the light blinking with each fire. This test works great and the tester is cheap.