Misfire on 07 kia rio

I have an 07 kia rio, I had a misfire in the 3rd ignition cylinder. When I opened it it had oil in it. So I cleaned it out and put a new spark plug in it and change to a thicker oil. A few hour later wet to drive it and after five minute the car shut down. When I was able to get it to turn on, it started to knock. I got it check and said misfire in the 1st cylinder, So I changed out all the ignition coil one by one it didn’t work till I got to the last one, the knock went away for a few minutes then came back. So I put the originals back it and the knock is gone but it still misfiring with the check engine light flashing or staying light. Please help

Is this oil you found on the tip of the spark plug or is it on the shank where the plug boot fits over it?

Is the oil level at the FULL mark?

It wasn’t on the spark plug just the bottom of the ignition coil.

Yes it is full


“check engine light flashing” . . . severe misfire which may damage the catalytic converter

Heads up

You may have leaking spark plug tube seals