been through it before... it's engine oil sipping out from the head gasket. even when your engine is off, it will still sip out and will accumulate on the exhaust manifold. so once you turn the engine on, the exhaust will heat up as usual, thus evaporating the engine oil that has sipped on to it, creating the white smoke. I just hate the smell of burning engine oil, it smelt like rubber is being burnt.
So once all the engine oil has evaporated, no smoke will be visible.
at first i thought head gasket bocor, but it was not.. had to change the valve cover instead.. now no more awan nano, just driving like on cloud 9!