wet sparkplug, y?

[Mouse]

Hi guys, i just took out my E46 318i (1.9L) sparkplug for inspection, i found out its wet with oil, apa sudah jadi? btw, it seems that only the tread is soak with oil, but the 4 legged electrod seems to be ok. is it because 1) overfilling of engine oil 2) too much of high rev or high speed? 3) some parts that is not plug in properly that causes this? or anything else?

 

[teejay]

reasons

1. oil overfill
2. seals/gasket got hole, end of life,etc
3. over revving the engine
4. oil too thin