hello, I got a 1989 Civic 4 door fully loaded, no ac. It overheats in about 2 minutes of running. I checked the thermostat, new....I checked the rad, no bubbles....I checked the oil and coolant.....no other fluids in it. ....Checked the Head Gasket...no leaks anywhere.......plus no White Smoke in the back. Just cean exhaust.....anyone know the problem........plus fans kick in also............I'm stuck