Engine froze up when i was backing up very slowly . oil full and clean. starter was removed and checked. tried to turn engine by hand wont budge even a 16/th of an in. read on the on line manual that theres an engine brake but it didnt say what can triger it. i dont know no yet if the timeing belt went but if it did could that engage the engine brake? Is this possibly what happend ? or do you have any ideas . please help..