I have a 97 Chevy Blazer. It started losing coolant and running hot a few weeks ago. Problem became extreme last week. Found a leak in the water pump, replaced it and the lower hose this weekend. Had to jump it off to start it. Ran rough while idling and issued a white smoke from tailpipe. Ran ok once I started off, then ran hot again. Stopped and opened radiator cap. Cooled off. Started off again and went a few miles. Started running hot again and rattling. Stopped and cut engine off, let sit for a few minutes. Tried to crank again and it would not.