ok i have a 96 K1500 burban 150,000 miles. i have a antifreeze leak somewhere but its not over heating, its not running as cool as she usually does. I noticed the thermostat needle going pass 210 the other day, so i decided to put in some antifreeze, it was BONE DRY..... I filled it to the recommended level and i stood there and watched it drink it down in less than 30secs. Like i said its not running hot though, and its not hitting the ground....but i do notice when i turn her off i hear like this gurgling noise and im clueless as to what that is, os that related to my problem? Im changing the valve cover gaskets this week i noticed some oil build up around the driver side valve cover... i figured change both while im at it. someone please help me out thanks. And i also have a "SES" light in i will post the codes tomorrow when i go get her scanned. Oh ya my heat works when it wants to as well.

 

Welcome to the forum.

Check the water pump weep hole(s), crankcase for water, and exhaust for water vapor.

Did you get it filled? If so, does the heater work then?