The cam-sliding-plate-thing broke off the rear exhaust side rocker arm which eventually led to me just removing my head to inspect everything. But this is the furthest I've ever gone into working on a vehicle, so I don't know what to look for..

Anyone knowledgeable that could comment on the condition and such of my engine based on the pics? Any info is greatly appreciated. Thanks!

 

the head appears to be missing an intake valve, #4 cylinder.

 

Whoops I'm sorry, should have mentioned, I took a valve out, lol.

 

I'd say them piston faces could use a cleaning before the head is put back on. Your coolant ports look a little plugged up too. Make sure you get the deck and head surface CLEAN before you intall the head. I'm used to working with a cast iron block and head, so I just used a grinder with a wire brush wheel, and a rag with some brake clean to clean the surfaces. But a grinder and wire wheel may be too agressive for aluminum

 

What do you think is going on here?

If those are "scuff marks" you may have a damaged block (and rings and maybe piston). If it's just carbon (comes off with a Greenie, and looks good underneath), it still got there somehow (bad ring?)

Or maybe it's just a lighting issue.

You really need to clean up everything. You might be able to visually inspect the head for cracks once you get it cleaned. Of course, you need the mating surfaces of the block and head clean before putting on the gasket. I'd start with a light touch with a razor-scraper to remove carbon. I don't like using a wire wheel even on cast iron; you can certainly round corners. You can get "conditioning" pads for a die grinder https://www.harborfreight.com/2-in-c...kit-69777.html that are like Greenies; I've had luck with them.

If you plan to reassemble this engine after inspection, clean up all of the parts. It may just be me, but I hate handling greasy parts.

 

that looks like its just the side loading wear marks that all engines get over time. It happens when the rods are at and angle pushing the piston up the clyinder causing there to be a slight side load on the pistons. This causes the skirts to lightly rub the cylinder walls and over time it polishes it smooth leaving that mark. As long as it's not scratches and it's not losing compression. It's still a healthy engine. Just don't slap new rings on it without making sure the cylinders are in round, and at least honed, prefferably a minimal bore.

Now this engine had just shy of 400k miles on it. Notice the still decent crosshatching, then the polished down area, it not a great example cause this one it scratched up a bit. But things like the last pic are what you should really worry about. It didn't smoke but had a inconsistent but frequent misfire at an idle with that cylinder

 

Is it normal for the cooling passages to be so rusty?
Mine haven't looked like that.

 

It's probably just from sitting with the valve cover off for a few weeks before I had time to dissasemble it. Will hopefully be gone in a few hours after I am done cleaning everything.

 

 

In the first two pictures, the back cylinder looks really full of oil and soot. In my experience that's indicative of a cylinder that is badly misfiring. I'd want to know the "why" of that before I went much further.