Cautionary tale Prius Gen3 DIY Head Gasket Gone Wrong with Parts Cannon New Video Series from Pine Hollow Diagnostics Clearly the Priuschat community did not help this disaster
Part 2 resolution At least two issues both owner self inflicted Good summary at the end of this video
I'm surprised the hydraulic lash adjusters were still in place. I had the impression some oil pressure is fed to them, which I'd have thought might have pushed them out of their places.
From the repair manual: I think there's something wrong with this pic: Should the $2 item (valve rocker arm) on the right side be mirrored left/right? On n the next page, this picture seems more realistic: Blow-up of exhaust side: ^ the yellow-highlighted portion I believe is the ball bearing he notes in the video, saying it should be over the hydraulic adjuster. (These are on page 11/12 of 196, bottom link in my signaturure.)
Pic looks OK to me. It's not showing two rocker arms facing each other. It's showing one rocker arm, and the right (○) and wrong (✖) way to install it. The ✖ way, you can see, does not have its domed end securely sitting on the lash adjuster, so its valve end is barely even pushing on the valve. If installed that way, the rocker is probably not going to stay put.
