Pontiac Repair: 1999 CHEVY MALIBU, combustion gases, circulation issue

Question
Hello Todd,
We are having overheating issues with the 1999 Malibu.
It is a 3.1 - 6 cylinder. We have replaced the intake valve, thermostat, water pump, radiator cap, new hoses,new serpentine belt and flushed it twice with cleaner. Each time we bleed the line and top off the fluid.Sometimes it overheats right away and sometimes it takes a while.There is no anti-freeze in the oil or any white smoke from the exhaust.Each time it overheats it pours out of the overflow.
Any suggestions on what we should try next?? Help!!!!
Thank you,
Stacey

Answer
Hi Stacey:
well it can be a few things. #1 that engine is really hard to bleed the air out of being that the radiator is lower than the engine I makes it hard to get the air out of the system. There is a air bleed valve on the pipe that runs across the front valve cover you may want to run the car and open that bleeder up slightly to expell any air. The other thing is when this gets HOT does the cooling fan come on? If not you may have a fan issue? When this car is getting hot do you get any heat inside the car? turn the HVAC to vent position turn the fan on high and temp to hot and see if youi are getting any heat in the car? If not you may have either a circulation issue or the heater core is bound up with air.. Lastly it may have a head gasket issue where 1 or both of the head gaskets are blown and the combustion gases are getting into the cooling system. You may not have a "smoke" issue out the tail pipe if this were the case. Good luck :)