Q: I have white smoke coming out of exhaust and engine running rough.

Hi There, It sounds like you may have a failing cylinder head gasket allowing coolant to leak from the water passages into the cylinders resulting in the coolant being burnt in the combustion chamber with the fuel. If this is the case, you may also notice a bit of white smoke coming from your exhaust which is a product of the coolant being turned into a steam like vapor. Lots of white exhaust smoke on start up is usually a sign of a head gasket problem. If the leak is very small, or leaking into adjacent cylinders, there may not be much smoke upon starting up, and yet still enough coolant may be pulled into the combustion chamber(s) to produce a strong sweetish exhaust smell. Generally, over the long run, this particular problem will continue to produce more engine problems. I would recommend having an expert from YourMechanic come to your location to inspect your car’s running condition to determine what may be causing the smoke coming from your exhaust.