A Little Help Maybe~ Thanks

[charlaa]

just bought a 94 gs 300, and i did do the research, the same problem other member had, bubbling in the reservor tank..and 'flat' upper radiator hose!! someone told me is blown head gasket or maybe have to get the air out by press the upper radiator hose,..

here is a brief story. After a week, today it just act abnormal, the temp gauge show it went up to upper middle, i opened the hood and found out the upper radiator hose was 'flat', then i just unscrew the radiator cap to make the upper radiator hose 'fat' again, since like no air can go through. and there is bubbling noise in reservor tank...wat cause this problem? sigh, just bought the car with 160k and dont tell me it got blown head gasket

the previous owner told me he had changed the timing belt and water pump, and i can see the water pump is pretty new.

there is no sign or coolant leak or coolant lost, wat it might be?? just change the new radiator cap but it still wont help..