when i first start the car for the day it sounds good and runs very very good. once the car reashes 180+ this loud annoying wierd noise comes from underneath me engine right around where my timing chain is all the way to the back possibly. i can hear the noise from the front of the engine then in the back? i was told it may be a main bearing?

if this is the problem what am i looking at to spend in fixing it?

 

i mean reaches 180+ degrees....