a little bit of white smoke from engine

i just go my girldfriends car on the road after its been sitting for 3 years. everytime we come to a stop, a little bit of smoke comes out from under the hood, but only on the drivers side. i replaced the thermostat. I was thinking, its either because there is caked up oil around the head, one on the hoses is bad or its a blown head gasket. but it it doesnt over heat. anyone with info please help.

White smoke is coolant entering a cylinder -- either a blown head gasket, leaking throttle body coolant lines, bad intake gaskets, or a cracked head.... If it goes away when its warmed up, some white smoke when it is cold out is normal.....

Also could be contaminants burning off the exhaust manifold.... harmless, but annoying.