So, today I made the "bubble test" and I have videos for you to discuss it.

When I started the car, there were no bubbles, but the coolant level was still rising, I mean it was still going up and overflowing, all the time. It looked like the engine is going to empty all the coolant:
http://www.volny.cz/veitel/prelude/o...t/overflow.mpg (1.2MB).

Once the thermostat opened, the bubbles started to go out of the radiator, even at idle, even when revving:
http://www.volny.cz/veitel/prelude/o...t/bubbles1.mpg (1.5MB).

So, it looks like a blown head gasket now, right?