So I changed my spark plugs at 43000 miles. I put in NGK Iridiums. The front 3 were a piece of cake. The rear 3 were a real PITA. The front 3 plugs looked ok. But 2 of the rears have a buildup of oil on the threads ( not near the tip where the spark comes out). I went to the dealer and showed one of the technicians the 2 plugs with oil on them and he said it was not a problem. Told me it "just might be the way the oil pools in that area). He said as long as its not by the tip of the plug then you aren't burning any oil and there isn't any problem. My car runs fine and there is no check engine light or anything. I never would have known about this if i didn't change the plugs. Anyone ever heard of this before?????

 

Wow, that is strange!

 

Do you feel improvment in power, more smooth idle and etc?
our sparc plugs should be good till 100K miles.

 

No improvement in power. car rides exactly the same. I know platinum plugs are meant to last 100K miles, but i don't think i would ever wait that long to change them. I'm just concerned about the oil on 2 of the plugs and if it means anything.

 

What was the part number that you used?

 

i had oil on my plugs on my old car (93 Probe), but the plug set-up was the same. it was caused by bad "o" rings in the plug chamber. might be the same problem you're having. that was fixed under warranty... hope this is of some help

 

i was thinking the same thing. that sounds like a highly plausible diagnosis.

 

ditto.

 

the part was NGK ZFR5FIX-11

 

I spoke with 2 other mechanics that I know personally after speaking with the dealer. They all said the same thing that it is a small oil leak coming from the valve cover gasket and as long as it is only on the thread of the spark plug and not the tip that it is harmless and they wouldn't do anything.

 

Unless you are having issues, why replace the plugs???
They are suppose to be good for 100k miles.
Am I missing something or do people just have to much time and money on their hands?

 

This does happen when you have engines with recessed spark plugs. A little oil would be considered normal, but when it POOLS, it's a bad spark plug gasket located under the valve cover. If it bugs you, replace all six.

 

so, the consensus is this is a normal occurrence?

 

why replace the plugs, because wait for 100K and then try to take them out, i have seen some bad things happend like the threads rust ( aluminum head steel plugs together they creat a chemical reaction and they bond together) and then you can't get the plugs out and usually what happens is that the threads in the head get stripped, and then you can try to fix it or if your unlucky you have to take the heads off to repair them, $80 worth of plugs evey 50k is not as bad as 2500 worth of damage for waiting, i have changed mine at 45k and it idles smoother, i used the oem ngk double platinums and i got a little better gas milage too.