Pontiac Repair: over heating

Question
I bought a 2000 Grand Am GT yesterday with the 4.3l. They said they put new water pump & thermostat in it. I put another thermostat in it too just in case they had gotten a bad one. Over heats really quick. Nothing came out (coolant) when I changed the thermostat & the coolant reservoir is full of coolant. I opened the bleeder too & nothing came out besides steam. Fans work great too. Any ideas or suggestions would be greatly appreciated. Thank you for your time & assistance.

Answer
hi darin
that engine is very touchy for getting the air out of. it can be just as simple as keeping that screw open and slowly fill the purge tank with coolant. and when you start the engine keep adding coolant to the tank and the air should burp out. it's a slow process don't let the engine over heat. the other possibility could be that it has a blow head gasket(S) and that is why you can't purge the air out. that 3.4 V6 is noted for head gasket issues if it was run for an exteneded period of time low on coolant they most certainly have head gasket issues and then you combustion gas from the cylinders gets into the cooling system and the engine will over heat pretty quaily and you will never get the air out of it.