i changed some ac rapidfires in about 6 months ago and recently had the intake cleaned (for free at school) and i pulled a plug to see what the chemicals did to the ends. not bad a little red and some carbon deposits. so i got some ngk tr55's and chenged them out today. the rear plug on the pass side (by the firewall) was absolutely HORRIBLE, the ground strap was white and fuzzy looking so was the shoulder of the plug the electrode was pitted and the inside was pretty dark it also had oil on the threads as i pulled it out.

the rest of the plugs look fine compared to each other

i did a compression on that whole side of the motor and they all cam out to 175-185psi

185 on the wet cyl, go figure

anyone else have this problem?

 

I haven't changed mine yet...less than 30K on the truck.

Maybe a bad valve guide or valve stem oil seal (oily residue). Possible bad plug/wire/coil...but you didn't say anything about misfiring.

Check that plug after a few thousand miles.

 

Yes. My 55's all came out looking like dry, orange, pitted hell after 12 months. I was getting pinging over 5800 maybe becaused the gap had opened up so much.
Switchd to TR6's 3 weeks ago and my mpg avg is up by 1.8 on the DIC and it runs smoother. I've been meaning to check them this week but haven't found the time to get in there...

 

I started out using the NGK plugs,and I had the same problem. I was only getting about a year out of plugs. Fu*k That! I went to the AC Delco 41-985 Iridium plugs, and they've been in for 2 years now with no problems at all.

 

You had no oil on the electrodes so the guide,rings,etc. are probably ok. A little oil on the threads might be from a vc gasket or a spill.

Maybe that plug was not gapped right or was somewhat defective.

 

well it's still driving good so far

i didnt have a misfire that i could notice

i'm hoping it's jsut a v/c gasket problem is i cant see for **** back there

i'll pull the plug in a few tho and check again