954x4runner

Hi everyone
My last main thread about my headgasket was here : https://www.yotatech.com/forums/f116...tumped-241306/
feel free to read it if you have nothing better to do.

Well i got the heads off today, turns out cylinder 1 is the culprit.



Quick question. There is one coolant passage on block that seems "blocked off". All the coolant passages on the headgaskets seem all there but theres a passage on the block that doesnt go thru.
Heres a pic, its the passage on the bottom right.



Not sure if its supposed to be blocked? But thats where the gasket failed, and let water/coolant into the combustion chamber.

Also why dont all the coolant passages on the headgasket have the same dimensions as the coolant passages on the block/head? Most all the coolant passages on the headgasket only have a small hole as a passage and the rest is blocked off, like this




thanks in advance for your help

TNRabbit

It's to reduce the speed the water passes through there so it absorbs more heat. The engineers who design these things know a thing or two~

954x4runner

Got it. But what about that blocked passage? Does every 3vz block have that same blocked passage?

TNRabbit

I think so. I seem to remember one when I did my rebuild. I think I drilled a small hole in mine....

954x4runner

Awesome thanks