1999 gmc blowing cold air when heater is on - 1999 GMC Sierra

SOURCE: 2005 GMC air conditioning

hello wwwatkin,

i stated my post in the clarification post and you can not rate my solution and since rating is just as important to us as answering your questions, can you please rate me in this post?.

thank you in advance and i really would appreciate it if you rate me a fixya.

again, thank you,

drcool299

SOURCE: 200 gmc jimmy st heater

Had similar problem in my 2000 Jimmy. No hot air from heater. Had the shop (Midas) disconnect heater hoses at the fire wall and blow out the heater core with air hose. Got rust and junk blown out. Hooked up and flushed system with new anti freeze. Got lots of heat now.

SOURCE: 2001 gmc jimmy engine warm but heater blows cold air

Disconnect the heater hoses from the water pump and the intake manifold. Get a compressor and blow out the hose (put the air hose into the the hose that came off the mainfold. then flush the system and replace the antifreeze.

SOURCE: heater goes from hot to cold

I WAS TOLD IN THE PAST TO GET RID OF THE ORANGE ANTIFREEZE AND PUT IN THE GREEN IN ALL MY VEHICLES CREATES MORE PROBLEMS THE IT CURES THIS IS BY A SHOP I TRUST.I HAVE A 95/98 AND 99 BLAZERS.I HAD PROBLEM WITH VERY LITTLE HEAT AFTER CHANGING THERMOSTAT. HAD TO GET AIR OUT OF LINES BUY RUNNING IT FROM COLD START WITH RADIATOR CAP OFF UNTIL THERMOSTAT OPENED AND LEFT IT RUNNING UNTIL I SAW NO AIR BUBBLES COMING OUT OF RADIATOR SEEMED TO CURE PROBLEM

SOURCE: 2002 GMC Yukon blows cold air from the front, rear works fine

check you antifreeze level and make sure its full