How reliable is Blue Devil for a blown head gasket?

I think there might be a blown head gasket. One guy I asked he said yes because last fall when he changed out my thermostat, he suspected a bad gasket. A guy that looked at it said he thought there was a crack in the intake manifold (?) and that Blue Devil would seal it up. Are head gaskets expensive to replace? If they are, is Blue Devil a good temp fix? If I use the Blue Devil, do you think it might last me for at least 4 months until I have the money to trade my car in? (it's an 04 Impala) It's not overheating per se, the gauge IS moving up past the halfway mark and there is water in the oil.How reliable is Blue Devil for a blown head gasket?There is no temp fix for a bad head gasket, gotta replace it. And don't try one of those 'Head Gasket in a Can' chemicals that you pour into the radiator, they'll just make things worse. The crack in the intake manifold...can you see it ?? Blue Devil could be some sort of epoxy that you mix-up and apply to the crack. It could possibly be a temp fix on the manifold, and could last the 4 months. To change the head gasket, you have to remove the intake manifold, so it could be replaced at the same time for no increase in labour, only parts.How reliable is Blue Devil for a blown head gasket?If you have water in the oil you have a cracked head or block or, most likely of all, as bad gasket. It costs a lot in labor and about $100 for the gaskets. I never heatrd of Blue Devil but I doubt it would work if there is water in the oil.How reliable is Blue Devil for a blown head gasket?I have no expierence with blue devil I have had good luck with liquid glass for cracks in heads manifolds and blocks, if you follow the instructions to the letter. I'm not sure about gaskets but I guess its worth a try as head gaskets are not fun and expensive to have someone else do it.