99' Tacoma knocking sound from engine

Hello world,

I was driving for 30 minutes and I got this knocking noise from my engine, I pulled over right away. My truck shut off. I popped open the hood and the coolant was overflowing. The temperature gauge was in the middle. It wouldn't turn back on. Now it turns back on but this knocking noise continues. My father suspects it's either a head gasket or thermostat.

Any second opinions on why this is happening? This is my first vehicle.
I know more about software engineering and queer theory than I know about cars.

Truck specs:
1999 Toyota Tacoma 2dr Prerunner Extended Cab SB
170,256 Miles
2.7L I4

 

Welcome! You probably are going to need a motor!

 

Do not crank that motor again. Is your Check Engine Light on and/or was it flashing when that motor is running in the video above? There is no way that is a thermostat. You have a severe problem. Pull the plugs and see if you can put a long screw driver or long wooden dowel down each cylinder. Turn the block slowly with a wrench (clockwise) and make sure pistons 1 & 4 go up and down at the same time (same with 2&3). Have you ever adjusted your valves? Check clearances on them. Check engine oil, is there any metal shavings there? How much coolant did it puke out? I see no way you don't have to tear that cylinder head off and see what your dealing with along with pulling the motor to look closely at the bottom end (or drop the pan by lowering the differential) especially looking at the crank shaft, rods, wrist pins, balance shafts, etc.

 

Take a look at your exhaust manifold (passenger side) if there is a HUGE hole it it, it could make a sound similar, but i'm still suspect that you broke a valve off or lost a rod.

 

kind of odd for a toyota 4 cyl to go out like that... tell us how much oil is showing on the dipstick.

 

^this.. I have a feeling it was run out of oil.
I had a buddy throw a rod in a 22re years back and it sounded kinda like that but even worse. But that was a 270k motor that had been knocking for a few months

 

are going to fix her or sell her?

 

Check out your exhaust manifold. If it's cast, I bet it's cracked.

You can do a compression test to see if any valves are broken

 

that aint no exhaust leak boys. this thing sounds like its life is over.