you need to get a second opinion , atleast give us an idea of whats going on and we can give you a few ideas its like if a doctor said you have a life threatening disease, you know you would get a second opinion

in my case a mechanic told me my car wasnt worh spending 500 bucks on becuse all the wires were messed up, (he wanted 500 bucks to diagnose an electrical problem) i told him to fly a kite and did it myself, by process of illimination i found out the ecu was fried by the old alternator and when it gets hot it shuts down after 120 bucks or a used ecu and a whole 2 wires under the dash that needed taped up car runs great and i am happy

moral check twice and do once,

could be main bearing if he said master bearing or also throw out bearing,

is it making a sound or what