Engine Bearing or lower end HELP

Bearing or lower end HELP

i need some opininions i took my car over to me neighbor and he said that i might have a spun bearing or something def wrong witht he bottom end of my car. its a 01 with 107k miles. it tried to do the plugs and injectors yesterday but it made no difference. once i took it to him he knew right away but i want to know if i should take it to toyota or to my mechanic? he said first put drain the oil and put in like 20w50 to try and protect it then look for metal in the oil. then he said to take it to Toyota and see what they say. now i was looking at how this motor goes together and it doesn't look like this could be done in a few days. the bottom end is sandwiched between 2 pieces and looks like a big job. also do you think toyota will be you need a new motor cough up 6k for a new one

any help would be much appreciated