My 04 Tocoma 2.7l ate my spark plug & burnt up the coil. I can now look directly at the piston top through the plug hole. How much trouble am I in for? Will I need to pull the head off or can I remove the rest of the spark plug from above? Motor has 237K miles, Is it time for some new parts anyway?

 

https://www.yotatech.com/g/album/3213618

 

A couple of things:

Based on the damage to the top of the plug, I would say you had some serious arcing that eroded the plug. This may have been a result of the plug backing out a bit allowing combustion up through the spark plug whole or purely electrical.

The part of the plug missing should be steel and in theory could be fished out with a magnet... if it's still there and not disintegrated and passed through the exhaust or flat out melted from previously mentioned arcing and combustion leakage.

How bad was your truck running? It basically had a dead short in that cylinder. That damage appears to have some age to it.

 

Truck was running great on the way home from work & then started running rough like it needed another coil. I bought one on the way home. While looking for the bad coil I discovered the broken one. I wonder if I can remove the rest of the "Plug Threads" out of the head without removing the valve cover ?