New motor

sludge / varnish present enuf to stick oil ring is evident of slow running high by-pass

extended oil change intervals

crap ass oil

synth oil will rarely stick a piston ring under the above conditions..........it happens in the extreme

even so a wet compression test tells U Nothing !!

 

I'm going to go with oil sludge and varnish as well.

Longer oil change intervals are usually a bad idea.

 

So does putting oil in the cylinder really tell you if you have bad rings or valves?

 

https://tfltruck.com/2021/01/video-...us-expensive-problem-now-what-baby-yota-ep-8/

This might help.
When l saw it, I thought of the issues that you are having.

 

A wet vs dry compression test will indicate the rings. If the compression goes up significantly after adding oil to the cylinder, the rings are worn.

 

Called the local machine shop this week. He estimated about 500 bucks to bore the block, polish the crank, and install new pistons and rings. It'd be another 500ish to rebuild the head.

So now I'm just waiting for my work trip to finish so I can pull this motor. I'll have to wait on ordering parts because we don't know exactly what we're going to find when everything gets torn apart.

With any luck I can reuse the pistons, but I have a feeling that's not the case. I'm going to contact yotashop and find out the quality of their parts. Might just end up buying oem Toyota stuff and piecing everything together

 

That's a very good price for the work being done. I'd definitely recommend new pistons and rings.

 

OP, hope everything is going smoothly. Idk if you were already doing it or not, But for future reference if your engine is burning that much oil , go with a thicker weight til you can fix the problem. It’ll slow the burn.