KA dead, cooling system suspected, temp gauge outta wack

[SilviaSativa]

I just bought a waterpump and thermostat not too long ago because my heater was out. Yesterday I replaced my fuel filter with the Z32 fuel filter, and also ran some Seafoam through the brake booster line.

Today, RAN GREAT...I was getting off the highway exit ramp, slowing to a stop and the engine died. I checked the gauges and everything was normal, temp was fine. Restarted it, made a god awful-clinking (whizzing?) sound. Had to keep it reved up to keep it running. I pulled into a parking lot, it died on the way in. Popped the hood, VERY hot, smoke coming from the bottom of the engine bay.

Get this, when I turned the ignition off and back on, the temp gauge was maxed out. Well I tried taking it home after it cooled, but it didn't make it, had to tow it the rest the way.

I checked out some other posts, and the first thing I am going to do is replace the waterpump and thermostat I already purchased. I'm most concerned about the temp gauge reading normal while the engine is running, but after it dies, I cycle the ignition and the temp gauge maxes out!

Could this have something to do with the water temperature sensor? I tried searching on this too but I am

[C-Kwik]

If it's anything like the S14 KA, then it uses two separate sensors for the gauge and for the ECU. Check to see if any codes are stored by the ECU. I doubt the temp sensor would cause the motor to overheat. If it's overheating, you likely have a problem with your cooling system.

[NISTECH]

you may have had a huge air pocket in there and coolant was not circulating properly. Also comfirm you installed the t-stat properly. I have seen bad t-stats out of the box. But since your temp gauge was reading right then jumped up I am more inclined to suspect an air pocket.

[SilviaSativa]

My brother and I ran the compression test today. Not good.

1st Round:cyl 1.) 175 2.) 99 3.) 75 4.) 100

W/ Oil Added: cyl 1.) 235 2.) 125 3.) 100 4.) 170

Stupid me forgot to depress the accelerator pedal throughout the whole thing. We tested again on cylinder #3 with throttle fully depressed and we got 95, which I think was 5 psi lower because the oil was dispersed more than any thing else. Also, these numbers are from a cold engine since it's obviously not running.

The piston rings are worn or damaged according to the FSM. Gonna have to pull it and see how far the damage spread, check the block and cylinder head for warpage. I wonder what else?

I hope I can just rebuild this engine. A turbo is out of the question for me but do you think I should spend the money on high compression pistons and drop two, maybe three grand on an NA engine? You know, just to hold me over until I move out and get a real job an all that to lay out for an SR.

Working at our pace now, we'll be lucky to have it running again by the end of summer. It's so intimidating to think of the work involved pulling and rebuilding your first engine, if I didn't have the Internet I'd have no other choice but to take it to a shop. Gonna have to suck it up and dive right in.