Ignition Coil Question

[Chriskaw440]

Last night I was listening to my engine as I changed oil and soforth and could hear sound, kinda like if you are standing near high tension power lines...that static/electric buzz kind of noise, and it seems like its coming from the ignition coil which is of course located right next to the plenum. Is that normal? Just seemed a bit loud to me. Do ignition coils start to show any signs of pending failure or do they just up and quit working when they go bad. Never changed mine...its the original for all I know.

 

Just put new dist cap and rotor on, new plug wires are next when pay day rolls around.

[Kingman]

Sometimes they will short a little inside and not produce as much spark, but usually they will just fail when the windings inside feel they've had enough.

 

Is it kind of like a zapping noise? Sounds like arching to me.

[M in KC]

Consider visibly checking it in a dark area or garage with the platic cover removed.

If it is arching externally it should light up like a Christmas tree.

[Chriskaw440]

Consider visibly checking it in a dark area or garage with the platic cover removed.

If it is arching externally it should light up like a Christmas tree.

 

yeah like a faint rapid zapping sound...steady. The plastic cover split and broke off years ago so its just the coil.

 

lately when the engine is cold...during warm up, it sounds like it is struggling to idle smoothly (missing a lot). on FIRST START...sounds great..smooth, then starts to stumble/struggle to idle smooth... Once its warmed up fully, idles beautifully. everything is new except for plug wires and coil. (new IAC, TPS, plugs, cap, rotor, lifters, vacuum lines, Oxygen sensor)

 

its like the 'in between time' from initial start to full operating temp that is stumbles quite a bit.

 

Oh and once in a while, the cranking sounds a bit weak when starting...most of the time its the usual FIRES RIGHT UP though (and the battery is still pretty new/ok)

[MY1PATH]

Consider visibly checking it in a dark area or garage with the platic cover removed.

If it is arching externally it should light up like a Christmas tree.

 

don't forget water in a spray bottle for this test. it will make any poor connections more appearant .

 

my MSD box, coil and cap all emit a same fast High frequency buz. I'm sure my stock setup did it too just not as fast or as loud.