My 94 runner all of sudden lost power on the freeway, it would restart and go a few hundred yards and stop again. When I got it two blocks from home it quit starting and whats making knocking noise not ticking. Intermittent knocks and LOUD. Also some squealing.
Had it towed 2 blocks.
So tore into it the idler pulley was failing busted it open ( got new upper, lower and belt BTW ) and the bearings were intact but really rough lots of resistance.

Then i got the cam off one side so far and I'm not sure how to tell if the lifters are damaged.

One thing I did notice is its very dirty in there LOTS of carbon.

I noticed three things that i think are the oil ports and it looks like they are clogged. Could someone verify this. Pics attached.

And if they are clogged this may explain the knocking right? I was gonna check the rod bearings too?

 

I got the other cam out and its shot, bearings shot. Guess I'll look for a new head.