Basic problem here is poster has screwed his engine because of local mechanics, now if he takes his car to Toyota and gets proper diagnosis and estimate of work he can decide what to do next.. it is a fact Toyota overhauled engines last longer then other overhauls..
There is no mechanic who can replicate 2 similar swaps.. one guy gets a swap and its working flawless for him but the other guy stumbles upon problems.. There is NO guarantee of of swapped engine since you swapped did you give warranty ? toyotas work has warranty
Mine is 2nzfe