Oil on Spark Plug threads and Tips..., Have pics of problem... Options

[Princess_Sparco]

When i first bought the car 2 years ago and changed the plugs. I noticed that there was some oil on the tip of 2 of the spark plugs. It didn't bother me too much then. A year later i changed the plugs again and there was oil on 2 of the plugs. On the thread and on the ground tips. Just recently I changed the spark plugs again, but this time, the same two plugs were dripping oil. the threads and the ground tip was covered in oil.

can anyone point me into a possible direction as to why this is happening? I originally thought it was the valve cover gasket (spark plug gromets) but wouldn't it leak oil on top of the spark plugs if that was the case? There's oil on the tip of the plugs which suggests to me that oil is leaking into the combustion chambers. I did a compression test awhile ago and the numbers aren't totally off. unfortunitely i dont' have those numbers anymore (lost them). if it helps you find my problem i can do another compression test.

[Insanity-74]

I`d agree with the good old rocker cover gasket problem (valve cover), Celicas are prone to these leaking tighten the rocker cover down, if that dosnt cure it, remove the rocker cover and buy some gasket sealant...the red stuff, not the blue Gell stuff, and apply this around the spark pulg hole seals. Looking at your plugs, one and two look OK, but three and four look cracked, this will cause the spark to arc out against the engine and could well be a cause of the rough idle.....obviously they will need replacing if they are cracked.