2000 blazer heating problem

I have a 2000 blazer ,I have no heat,I changed the thermostat, heat worked some for about 10 minutes,then cold again, bottom heater hose is hot- top hose is cold, orange anti-freeze looks like clear orange Tang, any ideas of what's wrong and how to fix it ?

I have a 2000 blazer ,I have no heat,I changed the thermostat, heat worked some for about 10 minutes,then cold again, bottom heater hose is hot- top hose is cold, orange anti-freeze looks like clear orange Tang, any ideas of what's wrong and how to fix it ?
This is a thread titled Basic Cooling System Advice found in the HOW TO section at the top of this Forum.

http://www.automotiveforums.com/vbu...ad.php?t=456944

Click on it and read it. Hopefully, it will help you. It sounds like your Heater Core is plugged.

Provided the engine is achieving and maintaining proper operating temperature: If a vehicle loses heat at idle, or will not produce approximately 130 degree F heat from the ducts, it could be an indication that the heater core is starving for coolant, or that the flow is restricted. Make sure the cooling system reservoir is at the "FULL HOT" mark on the tank. When a cooling system is low on coolant, the heater core is the first component to lose coolant flow. This is inherent with the design to: #1 let you know there is a problem, and #2 keep coolant in the engine block to help prevent overheating damage. The reason this happens is because the heater core is the highest point in the cooling system, therefore, care must be taken while re-filling the cooling system after maintenance to ensure all air is purged out. Once the radiator cap is installed it is nearly impossible for this to happen on its own. Try this procedure to “burp” the system. Turn the HVAC controls to “HEAT” and the temperature setting to full hot, fan speed is not all that important. Have a gallon or so of the proper coolant handy and remove the radiator cap. Run the engine at approximately 1500 RPM until the engine reaches operating temperature, (you will notice coolant moving in the radiator, and probably some bubbles too). Continue at 1500 RPM while making sure the radiator is near full at all times. Brief and quick increases in RPM will help to dislodge any stubborn air pockets trapped in the system. As the cooling system “burps” be sure to keep the radiator near full. Once you're satisfied all air is purged, make sure the radiator is full and reinstall the cap. NOW you can let the engine idle. Fill the reservoir to "FULL HOT" and take her for a test drive. If this doesn’t cure the problem, there is a possibility that the heater core itself is restricted, in which case reverse flushing it may help. Diagnosis for a restricted core is done while at operating temperature and 1500 RPM. Both inlet and outlet hoses at the heater core should be very close to the same temperature. They will be very warm, but not so warm that you can’t touch them. You should not notice a temperature difference between them while touching them with your hand. NOTE: Some vehicles use a blend door in the heater case behind the dash to blend outside (cold) air with heated air from the heater core. These doors can be operated either by vacuum or mechanically by means of a cable. On these vehicles, the position of the temperature control means nothing as they have full coolant flow through the core at all times. If the hoses have a noticeable temperature difference, the core is restricted and needs replacement. Other vehicles use a water valve to control coolant flow to the core. These valves can be either vacuum operated or mechanically by means of a cable. In either case, make sure the valve is open allowing coolant to flow through it while testing the temperature of the coolant hoses. If you’re not sure if your vehicle has a water valve, call your neighborhood dealership parts department and ask for the part number. If they give you a number, ok. If not, guess what? You don’t have one! Hope this helps. OM

had the same problem with 1998 heater core pluged
flushed system works great know

I have a 2000 blazer ,I have no heat,I changed the thermostat, heat worked some for about 10 minutes,then cold again, bottom heater hose is hot- top hose is cold, orange anti-freeze looks like clear orange Tang, any ideas of what's wrong and how to fix it ?

Sounds like an air bubble trapped in the core. Read my previous post to remove it.

The fact you state, Had heat for about ten minutes and then no heat. Look for a loose, or poor connection the connector going to the top of your thermostat housing. My brother has a 1999 blazor and had no, after replacing the thermostat, had heat for about five to ten minutes and then no heat at all. He brought the truck over to me and like you, I didn't know what is was, since he had already replaced the thermostat.
Knowing the GM has had a lot of problems with their connectors. I started with the thermostat housing and was going to work my way back to the heater core. Fortunately it was the connector on the sensor
at the top of the thermostat housing. He has heat now. And he says it
has never heated like that before. The best heat he has had since he bought the blazer. Let me know if that helps or not, Then we can look at other posibilities. Also check out Blazee's link for heater troubleShooting
This information is original GM documents.
http://www.automotiveforums.com/vbulletin/showthread.php?t=503195
Thanks
Southern