Hey everyone,k im new but here is the scoop, i bought my 2000 blazer in april 2012 and never had a problem with coolant, all of a sudden the weather got cold and when i started using my heater the coolant kept dissapearing from the resevoir. I checked oil cap, fine, trans fluid, fine, i highly doubt its head gasget but control panel for heat gets really hot and so does hoses leading into the fire wall, the only thing i can think is heater core is clogged and evaporating the coolant any ideas?, i havent got a coolant flush yet.

also when i used the heater for a long time i would not get no heat,k can this be a fuse or lack of anifreeze?

 

So there's no coolant smell on the oil cap, dip stick or exhaust? If not then I would back flush the system including the core,block and radiator. Then be sure to burp any air out of the system.

 

yeah there is no coolant smell anywhere, i think i should just do what you said then, just a money issiue at the moment.

 

A flush is cheap to do and requires only a flush kit and water. Then the antifreeze to fill it back up. I'll often just remove the heater core hose going INTO the heater cor, then use a length of hose and spare pipe to make an extension to hang outside the engine compartment. Then open the radiator, put a hose in it with the water running and turn the car on.

Then I back flush the heater core (not back into the system). If you want to be really thorough you can flush the last 20 seconds with distilled water, than fill it up with half/half distilled water and antifreeze. Keeps mineralization from occurring.

As far as the coolant disappearing, check anything to do with cooling. The reservoir tank, radiator cap and pressure release hose, heater core lines, heater core, and water pump should all be checked for seepage. Just because you can't smell it doesn't mean it's not there. Be thorough, take your time, and look for drips right after running the car hot.