do not drive the car... your big ends/rod knock will get worse and you can damage your crank severly
i'm still not with you about the thread in the back of the head lol.... i know that at the back of the head there is a large union which heater hoses come off which is part of your water cirulation... is this on a 7mge 3.0 non turbo?
for rod knock you will need to either drop the front crossmember or remove the engine, you will need to drop the sump and take your crank and pistons to a machine shop for grinding... take it to a trusted machine shop.. have a look around locally.. get some quotes... find out if anyone you know has had this sort of work done and where they took it...
i think you will find another complete engine if it's a 7mge for about $900 maybe.. i think that's the going price over there.. 7mgte's are about $1200... ring round some wreckers and see what prices they have for you
if you aren't experienced in rebuilding engines i would either suggest you get a machine shop to do the work for you or just buy another engine and put it in
let us know what you find out and what sort of prices
