today just picked up my car from shop 09 535i xdrive 130k just had the the oil pan gasket done belt got into engine and was giving the oil pressure low light(1400$) bolts stuck in block removal 350$ . So i picked up the car ,car running fine after about a mile and half into my drive the car gave a slight jerk after i pulled off and then it started smoking crazy i pulled over saw coolant leaking . im thinking blown head gasket but how any ideas