Chevrolet Repair: 2001 Malibu, blown head gasket, spring side

Question
I have replaced the thermostst three times and when the Malibu is cold it will overheat. If I let the car warm up before driving it it does not?  A chemical test has been done and it does not have a blown head gasket?  Any ideas?


Answer
Has the thermostat been put in the right direction?
   Spring side toward the engine, flat side toward the radiator.
Have any additives been put in the radiator?
Is there a bleeder valve that allows the air to escape after opening the system?
Is it a system that requires orange antifreeze?