1991 GMC Sierra "heater" Questions

heater core replacement Inspect/Replace If it is necessary to remove the heater assembly, the cooling system must be drained before removing the heater core. When a heater core leaks, a new heater ...

heater blowing only cold air no leaking, new thermostat, hoses seem full of hot water, just does not get warm inside truck??help" you may have a clogged heater core or heater core bypass valve ...

Heater not working my truck has no heater and the temperture gauge is high Probably air lock in the heater core. While engine running pull off heater return line and be ready to put it back on quickly

At idle, Heater Core Return Line is flowing only 2000 GMC SIERRA 6000 VORTEC W/AC . Installed new 186 degree thermostat. At idle, heater core return line is flowing only one cup of coolant in 22 ...

...changed thermostat, and replaced coolant, still my 1995 gmc suburban blows cold air. Find the two heater hoses going through the firewall to the heater core both need to be hot at operating temp.

Heater not blowing warm air. Thermostat has been 1993 GMC Sierra 5.7L Std Cab Pickup Heater not blowing warm air. Thermostat has been replace as well as coolant top-off Check the water control valve ...

heater on all the time heater dials are off but heater on Usually a sign the blend door is stuck in the heater box.  The blend doors direct air thru the box and the vents.

heater blowing cold air. like air cond. on. i changed thermostat If the car is otherwise running fine, then the thermostat is almost never an issue. you need to take a look at the heater core and any ...

93 gmc sierra heater not working I have a 93 GMC Sierra 2500 diesle and the heater is not blowing warm air just a few days ago the heater was blowing hot hot air now nothing THERMOSTAT REPLACE IF NOT ...

Heater was putting out hot air this morning, then it started blowing cooler air, I checked the heater hoses. Supply to heater was hot, return hose was pretty warm but not hot like supply. losing any ...