I was in the process of a spark plug swap out on my '05 C230 K 4 dr. sport sedan when # 2 plug came out drenched in oil. Oil was present in the bottom of the threaded plug hole. Oil level feedback showed normal. Buttoned everything up, using orig. plugs and started the engine. No problem at startup with smooth performance during warmup. Recent oil change, but I can't account for any problem that would effect # 2 cyl.