Ford Focus Forum, Ford Focus ST Forum

Ford Focus Forum, Ford Focus ST Forum (
-   General Technical Chat (
-   -   What is my spark plug telling me? (

Sully313 01-09-2013 06:43 PM

What is my spark plug telling me?
My car started running like crap when it started getting really cold. Mostly Misfiring bad on cold start up and a bit on warm restarts. Then I threw a CEL with DTC Code P0302 Misfire on Cyl 2. A few days later the light went out but it was still running like crap.

My car has 77K on it so it was time for plugs, wires and fuel filter. I replaced the plugs and wires and it runs great again. Perhaps better than ever since I've had it. Problem solved, but.....

..... I am a bit concerned with the plug from Cyl 4.

As you can see from the pic, there appears to be some kind of corrosion or some other gunky build up on the plug. Should I be concerned?

elsolo 01-09-2013 06:55 PM

looks like ash deposits from burning excess oil in #4

those deposits will cause a misfire at the plug

Next oil change, pull the new plugs and take a look, see how much has built up in a few thousand miles.

All times are GMT -5. The time now is 01:11 AM.