Q: There is smoke coming from my car hood what is it - 2004 Ford Focus

Hello. This is a sign of a potentially blown cylinder head gasket. Often times, as a result of the car’s engine overheating, the cylinder head gasket is compromised which causes oil to leak into the coolant passages and water to leak into the combustion chamber of the engine. When the water is burnt with the fuel, this often times causes the white smoke you see. This also causes the coolant to be burnt instead of being used to cool down your engine which is why the temperature may fluctuate erratically. Eventually, this will come to a point critical enough to case major engine damage and the car will not run. I would recommend having a certified mechanic diagnose the overheating issue in person and advise you on a repair.