I replaced a head gasket on my 2014 Prius with 210k miles. Everything went back together fine, or it seemed. At startup, there was terrible engine noise and rough running (as would be expected with 3 intake rockers clanking around in the valve train). I pulled the valve cover back off to find the 3 intake rockers had come off. Any ideas what could have caused this, other that I'm an idiot and didn't double check that everything was in order before I buttoned everything back up (which I thought I did). Ideas appreciated!
In the last thread I saw here where something like that had happened, a mishap in reassembling and timing the engine had led to some valves being struck by the pistons and bent. The bent valves then didn't rise all the way to fully close, leaving room for the rockers to fall out. The repair manual does have some low-key paragraphs where it quietly talks about moving the crankshaft 40° or so away from TDC for certain steps of assembly and only moving it back when the cams are known to be in the appropriate spots. The kinds of low-key paragraphs that would lead some readers to say "hmm, sounds like they're telling me this is an interference engine and here's how not to clobber the valves." But for DIY purposes, it might be nicer if they had come right out and said HEY THIS IS AN INTERFERENCE ENGINE AND HERE'S HOW NOT TO CLOBBER THE VALVES.
