One Spark Plug Cylinder fouling plugs - performance bad - blue smoke

[Danny Merrifield]

Hello Everyone,

I have a 2000 V6 Mustang, 3.8l, cold air intake, true dual exhaust, no other mods. 110k miles.

I changed my spark plugs at about 80,000 miles for the first time. I noticed that the plug in the cylinder on the drivers side closest to the driver was in the worst shape of all of them. I looked at the plugs again at about 100k miles, and that same plug (drivers side closest to driver) seemed fouled already. I changed it again at 107k miles and things run smoothly for a while, but I start seeing symptoms again of poor engine performance (hesitation, strange idle, blue smoke out exhaust on startup). Doesnt the blue smoke indicate that oil is burning?

Could a bad spark plug wire cause all of this trouble? The plug seems fouled with carbon that can be scraped off, not oil or fuel.

Please let me know if additional information is needed. There is no check engine light at the moment.

Any help that you can provide would be much appreciated. Thank you.

 

[DakotaR]

Ideally, spark plug should be a dusty tan. White and/or pitted = lean; black, sooty, or oily = rich. Blue smoke definitely indicates the presence of oil. You may have a leaky valve guide seal which is allowing oil into that cylinder. Do a compression and leak down test to confirm. Oil is probably fouling the spark plug which is leading to poor performance on that cylinder.