coil good or bad?

[blownatx95]

so I have a few coils from a V8 SHO, anyway i can test to see that they are good besides from puting them on a car? I don't have a third gen myself so that is out of the question. can i measure the resistance across them? I know the first two gens inside and out, but i'm a little lost when it comes to the V-8. I'm learnin tho

 

[pascofan92]

Same here.I had missfire issues and process of elimination and a little help from Ford I found the bad coils-threw em out-and got new ones---not motorcraft cuz they are $200 a piece for a $50 part .

 

[SHOZ123]

Unfortunately it is very hard to tell if the coil is bad by measuring the resistance unless it is very far gone. Usually the coil fails because either the case or the boot is cracked and the coil shorts out to the valve cover. This does not affect the coil winding resistance until it gets to the point of causing damage.

But IIRC the windings should be around 5.3K.

 

[blownatx95]

ok so if the resistance is close and there is no sign of damage to the boot or the case anywhere its likely a good coil? i was just curious because i have some a member was interested in but i don't have a car to test them on and i did not want to sell a faulty coil.

 

[SHOZ123]

No guarantees. Used V8 coils are like used V6 plug wires.

 

[blownatx95]

lol nice

 

[Funmart6]

Same here.I had missfire issues and process of elimination and a little help from Ford I found the bad coils-threw em out-and got new ones---not motorcraft cuz they are $200 a piece for a $50 part .

What kind of coils did you use?

 

[Funmart6]

Unfortunately it is very hard to tell if the coil is bad by measuring the resistance unless it is very far gone. Usually the coil fails because either the case or the boot is cracked and the coil shorts out to the valve cover. This does not affect the coil winding resistance until it gets to the point of causing damage.

But IIRC the windings should be around 5.3K.

So, if the coils is shorting out to the valve cover, would there be an arc?
Could you run the engine in the dark and see an arc and be able to tell the location of a bad coil?

 

[SHOZ123]

Yes, there would be an arc. One that would be aggravated by water.