Champion 7989 Spark Plug Failed

[feetwet]

Replaced my plugs with Champion 7989's less than a year ago... Suddenly got a relentless misfire on cyl #4 yesterday... here is the plug I pulled. Any thoughts from the picture as to why this went bad? Should I expect the other 7 to have similar problems, or call this a fluke?

To quickly get back to smooth running I replaced the #4 plug with an AutoLite HT1 and a new coil on plug. (just in case it had anything to do with the coil... save a second trip to the parts store)

 

[Explorer_PL]

I had the same case. My new Champion failed very quickly. I just ordered a set of new Autolites.

 

[feetwet]

It seemed like the stock coil on plug was a loose fit on the Autolite plug for me... you might want to check the fit on one before you do all 8

 

[oconnells]

I've had poor performance with both the Autolite and Champion plugs in both my cars. Have switched to NGK's, and so far have been much happier.