over heats & drinks coolant fast.
 

I have a 2000 chevy blazer LS. It drinks a lot of anti freeze. I've tried radiator stop leak twice and it didn't work. In tha summer time it only blew out hot air. Now in winter it blows cold air but when it's warmed up it starts blowing hot air. I can smell anti freeze thru tha vents. It over heats til I put more anti freeze in her. What is my problem. Thank you.

#1 heat out the vents isn't instanious you don't get heat tell the engine is warmed up
#2 don't use stop leak - plugs sh## you really don't want pluged - I only have used it if it's extreme emergency and it's a several hundred mile walk home
#3 smell of anti freeze out the vent usually is a heater core leaking, Riders side floor board wet? doesn't always have to be but usually is
#4 any antifreeze in the oil ? does oil look like a milk shake? if so could be a lower intake gasket
#5 water out the exhaust ? If so could be head gaskets or cracked head or as in #4 a lower intake gasket
#6 It will over heat if low on fluid and intell all air pockets have been bled out of the system
In other words you have to do more trouble shooting on your own so we can have more information to lead you down the right path to fixing it as there is many things that can cause it :icon_dance-cpatch:

#3 no there's no rider side floor wet.
#4 I checked oil & don't look milky.
And my AC compressor is seems 2be no good. I'm looking into it.

Ac compressor will not be the reason your eating antifreeze but prob the reason why it was blowing hot air all summer lol - I didn't add last night check the water pump also :icon_doh: I musta been tired, they have a weep hole that when the bearing seal goes out it lets water leak out, Is the front of your engine wet below your water pump, any wet spots on or around hoses, radiator or on engine - drips/ wet spots on the ground under the vehicle when parked ? :icon_emm:

That is very tempting for a sarcastic person!!;)

To keep my response on topic, you have a leak in your coolant system and you will need to find it...

To start, I would flush all that stop leak out. Then fill up the system, burp air, etc. Purchase, rent, or borrow a coolant system pressure tester and pressure test the system with a cold engine. If you find any external leaks - fix them. If you don't find any external leaks, you will need to investigate further. In other words, intake manifold gaskets, head gaskets and so on...

Hope that helps!

Ok I've been working and haven't had time to look into this problem. I've noticed only when I step onto tha gas pedal my heater stays blowing hot air, if I don't it stays blowing cold air.

You may have a pin hole in your heater core,radiator or a small hole on one of your radiator hoses.If the water pump has failed, it will most likely have a leak at the bottom of it,where the hole is located.Most times you`ll have a small pin hole on a hose, but it doesn`t always physically leak water.The water evaporates as time goes along.Also check out your radiator cap, they don`t always leak water either.a bad cap will cause the fluid to evaporate most of the time.You may want to have a heavy duty flush through out the whole system, to try and get rid of the stop leak.

I found a bad leak underneath tha transmission. Also it only blows cold air if not pushing on gas pedal, once I push on it then hot air comes blowing out. I'm looking for a mechanic that can do a high pressure test to see where tha leak is located.