Well it seems that my water/coolant in the Blazer is playing Houdini. Most noticable after it's been sitting for a while (months). Found out the hard way this morning with steam pouring out, looked down and the temp gauge was at 260! Hopefully I didn't blow a HG. Checked the oil and it's not going in there. I see no leaks, not where it's been parked either. When it's got water in it, it cools just fine. Doesn't really get over 190*, even when it's hot out. Unless there is already a blown HG and it's burning it out, but I don't drive it enough for it to go through that much. Any ideas or suggestions?