I have a 1998 Chevy Cavalier 2.2L. I've had overheating problems lately. The radiator is 2 years old. Also, I've recently replaced the radiator hoses, thermostat, water pump and the serpentine belt while I was at it.

After replacing these parts I started the car and it held at a steady temp, the upper radiator hose was hot and the heater was blowing hot air, but white smoke was coming out of the engine near the spark plugs. Also, there was a bad smell coming from the heater vents. After driving it for a bit it began to overheat.

I started it a couple days later and noticed the smoke again. This time the upper radiator hose heated up, but the temperature never held steady and heater never blew hot air before it overheated.

Is this a blown head gasket, cracked head, a blown gasket (other than the head gasket), a bad heater core, or some other problem?

Thanks, Bill.