Q: 2.0 jetta missfire coukd i be a blown head

It may certainly be a head gasket or cylinder head issue. Remove the spark plugs being sure to place them in order. You ,may find that the plugs from cylinders 2 and 3 are a bit more ashy white compared to 1 and 4. Coolant may be leaking between those two cylinders and into the combustion chambers. The coolant may be sitting on top of the pistons until you restart the vehicle - the cause of the white smoke. Have a certified technician look into the misfiring to locate the cause. More than likely the head gasket is at fault and should be repairable. Replace anything that is removed during the repair process with new parts. While it is apart, replace the timing belt, tensioner, water pump, thermostat, and maybe hoses. Get it looked at as soon as possible as prolonged driving in this condition may cause more severe engine failure.