97 Cutlass overheating
 

Ok, I have the daunting task of trying to fix my aunt's car and save her a few bucks... She has a 97 Olds Cutlass Supreme SL. Its been having an overheating problem lately. Basically she split a line to her heater core and with all the leaking coolant she overheated the car, a few times. My initial guess is to replace the line fill the system and pray she didnt blow a head gasket. I replaced the heater core line, and after arguing with her boyfriend, also changed the thermostat. I refilled the system with the dex cool stuff and bled the system as best as i could before all i was getting was coolant from the bleeders. All in all it took about a half gallon to fill it up.

After running the car for about 20 minutes it quickly overheated. I checked the hoses running to and from the radiator. The thermostat was most definately opening and allowing proper flow to the radiator. I would also like to note that the fans turn on at temp, but never turn off cuz the car keeps heating up. After letting the car cool I cracked the bleeder again and got only air... The reservior never lost any coolant, there's no loss of coolant visible in or around the vehicle, but still it overheats and appears to be losing coolant.

I would also like to note that the LOW COOLANT light is lit on the dash. When i fill the car's engine up with coolant the light goes out, but after about 10 minutes of running the car the light comes back on.

TLDR VERSION
Replaced thermostat, radiator still new, fans work, no leakage of coolant under engine or in car.
However, still overheating, and appearing to lose coolant, but the coolant loss is not visible...

Is this a head gasket if there is no coolant in the oil and oil in the coolant?
There is also NO white smoke from the exhaust, nor is there water in the exhaust.

Please, any help would be appreciated.

They can be tricky to bleed at times, if you had trapped air that could cause overheat. I would try to make sure you have all the air out, fill with bleeder open, run till hot, let cool, repeat. I'm gonna guess this won't fix it as it's likely a head gasket (or more likely, warped head), but it's worth a shot first. A simple head gasket test is to put a pressure tester on, pump to about 10psi, then run the car, and brake torque it. If the pressure increases quickly, and steadily, likely head gasket.

I agree with the possibility that its the head gasket... I tried to bleed the system multiple times and after the first stream of fluid i shut the bleeder... i waited a few minutes and massaged the hoses while opening the bleeder again and all i get is a hard shot of straight steam... No fluid whatsoever... after letting it cool again the hoses started to compress. I think my head gasket is done for.

Any bubbles in the radiator while the car is running? If so, another sign the head gasket is gone.