Hi All. 04 neon sxt that has smoke accompanied by loud hissing noise that emits from the front part of engine compartment. Starnge thing is that it last for about ten seconds and then stops completely, as though it is some sort of valve that turns off. Everything goes back to normal for about 1 minute and it does it again. White smoke with hissing, doesn't appear or smell like steam. Any clues?
greg