Man I hate it when I can predict that the LS will give me some mechanical failure in the near future. Little did I know it would be a week after my post about replacing the drive train and how happy I was, but fearing the LS would do something new. Well it did, of course. But this time to be fair I probably can't blame the LS. This time it was a spark plug failure. In over 45 years of working on family cars and various mechanical beasts, I have never seen a failure like this one other than stories here and there.
Well anyway, I was driving home on the freeway at normal speed etc. Suddenly I heard an exhaust leak type sputtering. I figured maybe a connection to the EGR or some exhaust tubing had slipped or come loose. When I got home I listened to see if I could pin point the sound. It sounded like it was coming from the Valve cover coil cover on the driver side. I figured a horror story like a blown out aluminum head like was common on many of the aluminum Ford V10 engines a few years back. Helicoil time or worse. My scanner said number 7 misfire and ignition circuit problem with coil G(ie #7)
It was late and soon to get dark, so I waited for today, Happy New Year, yeah.
Took a closer look and noticed the coil cover plate had a foot long crack in it. Pulled the cover and found Coil 7 sitting sideways under the cover and the top of the sparkplug electrode broken off. Fortunately I was able to remove the plug along with what was left of the ceramic insulator and the plug center electrode.
Here is a picture...
View attachment 828471010
Notice the in cylinder nose portion of the insulator is missing. Not a good thing but too late by now, I drove probably 6 miles to get home with the sputtering sound, so the ceramic either blew out the exhaust or maybe the hole thru the spark plug body. Either way if there was any damage from the ceramic bouncing around it is done now. I could not see anything in the cylinder and did not "catch" anything with my flexible grabby tool(saves me more often than I like to admit).
Anyway, Tomorrow I walk to the local parts store since I don't want to go chugging around town. Good thing it is less than 2 miles.
The plug that failed was a Champion(I liked this brand for decades) which I replaced back in summer 2011 and it had about 65k Miles on it. Not expired per manual but maybe should have been done routinely at 50K even though on last inspection before summer this year, everything looked fine. The electrodes looked fine with no unusual wear other than being loose in my hand.
I am guessing this is one of those random component failures, 1 in a million(I have driven over a million miles and never saw one of these), and that the LS was not messing with me this time. If it wasn't a random failure I am wondering what may have caused this, did I suck something into the cylinder that banged into the plug? Probably not but I won't know unless I tear things down or something else bad happens.
Oh well, I was going to the junk yard for the after Christmas sale tomorrow, so I guess I'll pick the cover and maybe a handful of coils to tide me over til I can get some delivered.
Jim Henderson