Hi all, I've got a non-running '82 diesel westy with an AAZ engine, that I bought as a project. Discovered that one of the exhaust lifters had shattered, marking up the lifter bore pretty bad. Pulled the head, and while everything down below looked normal, each piston had a slight mark where exhaust valves had kissed it in the past. I'm assuming that's why the lifter was broken.
Fortunately, the van came with a spare used AAZ engine, and I pulled that head to swap. I'm thinking this head was not original as it showed little wear on cams, no cracks between valves and looked exceptionally clean, on an engine that supposedly had higher mileage (270k?). But what shocked me was to see those piston crowns had also been kissed. None of these are deep marks, maybe a few thou, but they sure shouldn't be there. They were shiny and not carboned up, showing that not a lot of use since they were hit.
I did some looking online where some dude was rebuilding his AAZ, and sure enough, his pistons also showed the same marks.
What the hell? Do all these engines show the same problem? What I'm left with here is should I be worried about my replacement head? Was it installed as new one because of the past damage shown by those marked pistons? Or did this head do that damage? How do you tell? The valves look fine and are seating fine.
I'm not sure if I should replace my lifters and valves, just my lifters or just install these very clean looking head? Is there really a concern for the valves given that there's barely any mark on the pistons? Valves aren't cheap; rockauto wants $34 each.