Piston/Valve contact

I removed my left head today on my 94 3VZE to diagnose some issues, and this is what the valves and pistons look like. I’m thinking the small chip in the pistons could be from the valves hitting, but I have no idea what caused that one valve to look all corroded like it does? I’m just looking for some advice to what these issues might be, I’m gonna get the heads resurfaced anyways and I wanna know if I will need to do a full rebuild of the engine including new pistons.

 

I would do a full rebuild including new crank, bearings, everything up or find a donor engine in good shape and less hours. It just depends on how much time, effort, and money you want to spend.

 

I’m thinking the small chip in the pistons could be from the valves hitting,

Hi:
When you say left head, do you mean passenger side or driver?
The 3 liter V-6 engine is a non-interference design.
Say, if the cam drive belt broke for any reason, the engine would cease operating immediately, and the valves would not hit the pistons.
Those semi-circular depressions in the piston tops, are valve reliefs, and are there for just that non-interference reason.
If that is the driver side head, and the offending cylinder is #6,(rear, closest to the firewall) then that intake valve is probably burned pretty badly.
The 3 liter engine has an exhaust crossover from the passenger side head to combine the output into a single system.
The exhaust from both sides of the engine combine directly under #6.
The head and gasket at #6 really suffer from double the heat that the rest of the cylinders don't have, and is a high mileage failure point.
If it is #1 on the passenger side, then that cylinder suffers because of being last in line for coolant flow.
The design people at Toyota sort of dropped the ball on this engine design.
Also just redoing the heads can lead to problems down the line.
The block must be checked for flatness and it must be determined if it has ever been decked for flatness in a prior life.
If it has already been decked more than 10 thousandths, then you are out of luck for a deck job.
The machine shop will check this, but you'll have to pull the motor, and bring the block in to them.
If you put fresh heads on a not fresh block, the gasket will fail in a relatively short time. (three days to 6 months)
If you deck an already decked block, and they plane the heads because they will be warped, then the valves will hit the pistons in normal running.
Plus by doing this, you have actually narrowed the V of the block, and the intake manifold won't fit any more; not by much, but the bolt holes won't line up.
I don't mean to rain on your parade, but you must think this out carefully, or you will get to do it all over again.
Good Luck.
Art.

Edit: Is that grey looking goop on the block in picture #1, an oil-coolant mix?
Did you take it down for a gasket fail, because of an oil-coolant event.
If so, a total rebuild is in your future.

 

Welcome from Wisconsin! Take the engine out and do a rebuild, make sure everything is 'straight', like the block, cyl. heads. Speaking of cyl. heads, think you have a burnt valve on the cyl. in question. If deck height of pistons is tampered with (resurfacing) you could find a head gasket with different thickness to compensate for the material taken off the block or cyl. heads., this process works on some engines, not really sure if that's an option on Toyota. Good luck, it'll work out.