White smoke from exhaust

Engine Cooling problem
1994 Mazda MPV 6 cyl Four Wheel Drive 155377 miles

Thinking to buy. Owner states that had a new water pump 3 years ago and thinks it was going again (didn't know if it would help) anyway said was driving and engine heated up a little and white smoke came out exhaust. Went and checked it out constant large amout of white smoke spurts out of exhaust on startup. No air bubbles from radiator, no milky or water in oil, but oil level is higher then thought possible! I know excessive oil can cause wite smoke but I am concerned about the statements made to me about the engine getting hot and thier worries about the water pump. But. With oil level don't know if they even knew what they were talking about! Help what do think tooo much oil or head