I have a 98 gmc Sierra k1500 z71 that I bought last week. It has 244xxx miles. I have a issue with it getting hot. It runs great when temperature is around 200. But for the past couple days it runs up to about 210-220 and when it gets around 220 it it falls on its face. Idles horribly and eventually dies. It has no power whatsoever and falls on its face. It has the 5.7 vortec in it. I thought it maybe has a leak but I do not see any antifreeze anywhere on the ground or visibly leaking. I checked the antifreeze and it was a little low but not bad. I checked the oil and no water in the oil. It is not smoking. It died coming home from work tonight. Once it dies it will not start back. It cranks good and I can pump the pedal and it will shutter and act like it wants to try and start but it won't. And it did the other night as well but after it sets for a few hours it starts right back. I know it's an old truck but is solid all the way around. I got it for cheap so I don't mind working on it. Any ideas or help pointing me in the right direction would be great. Thanks in advance.