2003 Hyundai Santa Fe • 98,000 miles

Have a 03 hyundai santa fe that has had 2 different misfires codes in the past month. 1st was cylinder 1, replaced coil and sprayed with WD40 and problem went away. 2 weeks later starts skipping again, this time with cylinder 3 misfire code--rather that replace another coil, I took out and cleaned spark plugs (new), wires, coils, and coated in dialectic grease. This fixed it and it ran great for about a week in a half. Now misfire 3 again. Going to change wires next. If that does not fix it, where should I look next? And does the fact that it went away with cleaning and grease coating suggest it is something with moisture rather than a more involved problem?
March 28, 2013.

Usually when 1 coil fails, the rest are getting there too. Thats why we reccomend replacing all when we do tune ups.


Mar 28, 2013.
Okay. In the santa fe there are two coils, one for each 2 plugs. So coil 1 does cylinder 1 & 4, and the other coil on cylinder 3 does cylinder 2 & 3. If the coil was failing wouldn't both plugs/cylinder attached to it be misfiring, not just one plug each time? I forgot to note this the first time, but the heat of the car when it has been running more than 20 minutes seems to exascerbate the problem. I have been chasing this skip for 2 months now, andit is getting old.

Mar 28, 2013.