(Tried to post once and didnt work so if oy did and double posted sorry about that) So I recently bought a 2000 xterra with the 3.3 v6 4wd automatic has 19xxxx miles, it made a engine noise but I figured it just needed a oil change easy fix well... took it to the mechanic the next day and he said it had a bad lifter tick and motor was probably shot, it ticks really loud and sounds like a diesel rather it's just started or been running for an hour, and when I go to accelerate on a small hill or encline it jerks and bogs down in power, my father said something about it could be a warped push rod of messed up rocker arm which could explain the tick and power loss, so before I go out and try to take the whole motor apart in the cold does anybody have any ideas or tips to fix it? I need to get this vehicle on the road and be dependable before I drive around with my newborn in it, any help would be appreciated thank you!