ALWAYS START WITH THE BASICS. FIRST CHECK THE TRANSMISSION FLUID LEVEL ( ENGINE MUST BE RUNNING AND COLD TO WARM ). THIS A TYPICAL SYMPTOM OF A LOW FLUID CONDITION. AS THE CAR WARMS UP THE FLUID EXPANDS AND THE LEVEL IN THE PAN RISES. THEN IT DRIVES OK. I THINK IT IS LOW ON FLUID, AND THE FILTER IS SUCKING AIR FROM THE NECK.