Help please - 1HZ landcruiser overheating!

[off-road]

Compression test will not show conclusively as one cylinder might be down on compression for a number of reasons.

The best gadget is a hand pump that connects to the filler neck that you pressurise the cooling system with and it has a guage to show if system holds pressure.

Given that it only gets hot in high load situations it could be a pretty tiny combustion leak that may be hard to detect.

[lojik]

If the crack is between a combustion chamber and a water jacket then I would imagine so.

Although I am just regurgitating things I've read/learned/experienced. I aint no mechanic