2005 Dodge Caravan Bubbling at Sparkplug

Recently had the waterpump replaced and the check engine light came on, mechanic stated it was plug #2. I replaced the spark plug and light came on, car was sluggish and felt like it was an alternator issue. Checked the readings and battery got 12+ then running it rated 13.5-14.5, I also notices smoke from the #2 sparkplug and a liquid bubbling up. Exhaust was showing white smoke. Is this oil? how can I fix this?