1995 Lumina suddenly oveheating

Yeaterday my daughters lumina suddenly oveheated. Husband changed coolant fan fuses, thermostat and water pump. Antifeeze is bubbling out of radiator. Upon squeezing both hoses it's evident there's air still in the system. No antifreeze leaks or white milky substnace in oil or white smoke from exhaust. At a loss?? The only thing we noticed is the fans are not coming on when car is heating up... Any suggestions? We just bought her the car 4 days ago and some friends have suggested it's a head gasket, but with no signs I'm skeptical. It's a 3.1 with 163,000 miles on it.

Welcome Aboard!

There is an air bleeder screw near the front (left) end of the engine, right above the black coolant transfer tube. There is also an air bleeder screw on the thermostat housing. With the engine warmed and running, each of those screws can be opened to allow excess air to escape from the cooling system and permit coolant to flow normally, without having to overcome air bubbles in the heads and intake coolant passages.

Regarding the cooling fans, the primary fan will not turn on until the coolant is above 226ºF, so it may take a long time with the engine just idling to create that much heat. The temperature gauge on the dash will indicate about half scale or more before the fan will turn on.

Thanks we'll try that today. Let you know what happens.