There are two coil packs. A diagnostics test revealed that the number 3 plug was bad. I had the plugs changed which helped but the point is mute if I don't fix the problem at it's source. I am planning to attempt changing the coil myself, as I have heard it is easy. Can anyone give me a detailed account of how to go about this?How do you change the ignition coil on a 2002 Kia Optima?
2 coil packs, that's a V6, right? Did you change the wires too? I did so on an 05 V6 Optima and it was half easy (front 3) and half nightmare (rear 3). I can't recall which one is 3, but the rear cylinders were a real b**** to change the plugs in, especially the right rear one. To get to them, you have to unbolt the intake, prop it up on blocks and it's STILL hard to do without an assistant.
If the coil pack was bad, the problem would be on every cylinder that it fed, not just one of them. I learned that one when my 1987 Chevy Blazer (2.8L V6) conked out by tracing the ignition system forward piece by piece. Start out by having a friend turn the engine over (crank it) while you use a voltmeter on the coilpack's output terminal. Put the positive lead on it, negative lead to ground (such as the hood latch). A good coil will output around 10-12 volts (my blazer did 10.73, compared to a new one doing 10.75). If it checks out, repeat the procedure at the distributor, or where the plug wires attach to for each cylinder. Since voltage is only applied in pulses for each cylinder (this is ignition timing), keep your eyes open, as it will be going on-off at 125 times per minute (idle speed divided by 6 cylinders)
If all the plug wire attachment points pass (10-12 volts), then it's in your plug wires or a fouled plug. Repeat the distributor test at the end fo each plug wire.