for online reference . i have comments but can't post em right now
lemme say this for now
been there ,done that .
replacing this pump wasn't the answer for me either
you mention boring the blocks but what about surfacing the block(s)
what block got surfaced what block didn't?
are you using a metal gasket ?
could you have switched hoses going to and from somewhere ? kinda sounds like one hose is pushing when it should be pulling ..thats assuming it's not a bhg .
i have had my car for 10 years . i struggled with the same problem for about 60k miles . water pumps hoses radiators you name it , sensors swicthes anything i could think of finally she quit .
i swapped engines , and blew another gasket after 10k miles this was a remanu from japan . went with the metal blew that one in less time and had finally had it . i resurfaced the block by hand . had the head surfaced by machine and then did the head by hand . the two parts are beyond smooth . can you say badda bing ?
i've dealt with 4 bhg's on two different supras ....... they really suck .
flat and smooth
the picture makes the flaws easy to see but with the human eye the flaws are not easy to see and you can barely feel them .
i know it looks like grand canyon , but you can see the difference that the lapping tool made .
when i got the head back from the machine shop the guy there thought i was nuts for touching the head after he finished it . but the head looked like it had grand canyon all over it and i could feel it too . lapping the head made a big difference.. hand beats machine