Ok, I need help, im stumped. I have a 96 Cadillac Devillle 4.6L and I've been having problems with overheating. I've done alot of work within the last week and nothing seems to work, I've replaced the following:
Radiator
Water Pump
Water Pump Belt
Heater Core
Temperature Sensor
Thermostat
Radiator Cap

*Fans come on around 222 degrees. There's white smoke coming out of my expansion tank when I remove my radiator cap. Checked my oil, and there's no coolant in it. Also, my air conditioner doesn't blow through the vents, don't know if that would affect anything.

Please help, I'm going crazy.

 

Suggest a pressure test of the cooling system to determine if you have a leakage.

 

Yes, I suggest the pressure test as well. If you have a blown headgasket this could definitely cause a problem. HG's don't always blow internally to the cylinders. If you have an external gasket leak you won't have any coolant in your cylinders getting into your oil.