Here's my story:
I was on the highway one evening when my temp guage suddenly shot into the red. Seconds later my car slowed and eventually shut down...wouldnt start up again. Opened the hood at the gas station and steam billowed from the engine for about 30 minutes. At this point I discovered the top of the (PLASTIC!) upper coolant elbow blown out (thanks GM). Did some research at home, coolant reservoir smelled like oil, coolant in the oil as well, so I figured I'd replace the LIM, so I did. Got everything back together and the car wouldn't start up, obvious signs of very little compression by the way it sounded. Pulled the plugs and they were wet so I turned the engine over a few times to get the fluid out and bought some new plugs as well. The engine still wouldnt crank. Pulled the new plugs again, and guess what? Full of water. So at this point without a doubt I have cylinder head issues. I planned on doing the head gasket change as well as get my heads milled. So I pulled the heads, took them to get machined at the local shop and received a call the next day after the were magnafluxed that both cylinders were cracked...FML.
Here's my hypothesis:
While I was on the highway, my coolant elbows failed, released all of my coolant, and the ECT sensor cant give me a temperature reading without having coolant passing through the engine. So at this point my engine was MUCH hotter than it was reading on the temp guage. Usually when I'm overheating, the DIC will say to turn off the A/C or whatnot. But my car didnt even have the opportunity to power itself down to 3 cylinders because it didnt even know it was too hot (ECT can't read air temp). Before I knew it, the heads were cracked. My suggestion to all who havent done so it to REPLACE YOUR COOLANT ELBOWS if you haven't done so!(When I pulled them from the tensioner and manifold, they disintegrated in my hand) They're cheap and will spare you this major problem.
Here's where I need some help:
I plan on getting new/used heads. If I find used heads, I'm going to have them machined without a doubt just as a precaution. Now at this point my block looks pretty clean and intact, no observable cracks from what I see. But I am afraid that since my engine got hot enough to crack two iron heads, I might have done some damage to the other parts in the bottom end (piston rings, connecting rods, etc.). Are those things that I should replace as well? Should I be concered with the cylinders being warped? What other parts should I look into replacing as well?
