piston ring life expectancy

[andy120]

What is a rough idea of piston rings. S00k's?

[geeves]

Many variables but the factory 4jb1 and 4jg2 engines in trucks are hitting 1000000km plus without ring replacement. Service them properly drive them long distances and they last almost forever.
In the Isuzu 4x4s we have evidence of 500k on a 4jb1 450k on the early 4jg2 and much the same on the efi version. The 4jx1 has had its own issues but if the injector sleeves never leaked and the recalls were done then I know of one that topped 400k still going strong

[andy120]

I think I have low compression (lower performance than the other one) and have a leak somewhere high around the #1 injector. I am conflicted whether or not to do a full motor swap or just do the head. Its done 400k.

[geeves]

compression or leak down tests only way to tell