my 95 monte ls V6 3.1 has this issue where it will over heat so about two days ago i heard a sizziling noiseunder my egr valve and i seen a stream of water coming from wat looked like the block im not sure didnt get a good look but i seen the water coming out in a constant stream so i was wondering if it could be my freeze plug i dont know were it is to start with and my heater will not allways work some times it will work but my car will start overheating and the hot lite will come on and then the light will go off it will drop alot of heat and the heater will start working untill it gets hot agian then no heat and will all happen agian. what u guys think????????:runaround:

Most likely the intake manifold gaskets, but try to visually pinpoint the leaks first, get a pressure tester on it.