I replace the hhead gasket on my car after i saw white smoke. like so much that you can't see. now with the new head gasket the car still smokes a lot and black oil is coming out of the exhuast. The oil doesn't smell like gas and isn't burnt. the oil pressue is also very very high passed 120. and the idle will be ok for the first 5 mins. and then the idle goes up and down and then dies. Does anyone know what is wrong ... Please help me.