My 1994 nissan gxe water coolant container is boiling, what is it ?

I have a 1994 Nissan Altima GXE. I noticed the water coolant container next to the radiator started boiling and evaporating the water inside, but my car is not overheating or being affected by this problem. How do I fix this, and what could it be? Please help!|||The overflow tank in most coolant systems traps excess coolant and allows for too much pressure in the system to safely escape. It sounds as if your coolant overflow tank is doing its job and I would not be worried. Be sure to check the antifreeze level when the car has cooled down to make sure that you aren't losing any coolant. You might also want to check the coolant protection level (measured in degrees) with a Prestone antifreeze tester. It's available at most autoparts stores and looks like a turkey baster. It will tell you if you should change your antifreeze. Too much water in the system can lead to frequent boil overs in the coolant overflow tank. Good Luck|||You could have just overfilled it. I had a tuarus with a coolant recovery tank that would boil out, and I would fill it back up every time. One time I didnt have any water to put in it, and it quit doing it.





It was part of the pressure relief system. The cooling system is kept under pressure at all times, Put if too much liquid is in there, it has no room to expand, and it could cause hoses breaking. But if your car has pressure relief, it will automatically let it run off.





But I could be wrong.|||It really is overheating, regardless of what the guage says or if it's actually stalling or smoking/steaming.





It could need a radiator flush, new thermostat, possibly water pump or seal for it.





Or maybe your fan motor or fan clutch is not working correctly if this happens more in city driving than on the highway|||Take a look at this link. It's a step by step and there's too much info to post here. Good Luck!!|||If it's boiling in the overflow container, it's also in the radiator, you need to ck your guage.|||WHEN IT'S BOILING WAIT A LITTLE AND SQUEZZE THE UPPER RADIATOR HOSE AND THEN THE LOWER IF ONE IS REALLY HOT AND THE OTHER ONE IS NOT THAT HOT IT'S YOUR THERMOSAT.|||Your car is overheating. You need to get it to a shop before you do some major damage to your car.|||check the container lid and replace it .