hi everyone, so this is my problem. 97 blazer 4.3 vortec 4x4 ls model.
its got almost 140k on the clock and the temperature got really hot one day so i changed the thermostat and it got worse, almost all the way hot. the coolant was dissapearing out of the radiator like crazy. its not burning it(to my knowledge)so i took the thermostat out and filled the radiator and it stays below half ever since, but it is still drinking coolant but not nearly like it was. i would like to put the thermostat back in so i can run my heat in the winter, but as of now i dont know what to think, i was told a head gasket might be worn. what do you think? it also isn't leaking anywhere or dripping out. any insight would be great! thank you!

 

How does the engine run? How fast does the coolant disappear? How does your oil look?

 

just did a recent oil change it looks good, no water in it or anything. the truck runs amazing as of right now. over a 5 day period i usually put a gallon of water in it, depending on how much/far i drive in those 5 days

 

I had a similar issue, though I didn't have as much coolent disappearing, but a noticeable amount was. It turned out it was the Lower Intake Manifold Gaskets which let it leak a little into the engine and out of it.

 

thanks dan for the info, how did u find out thats what it was? was it noticable that it was leaking from there?

 

It wasn't very noticeable but if you looked closely enough you would notice a small break in the gasket and remnants of something burning off the Lower Intake. After taking it apart it was a bit more noticeable on the back of the engine block. How many miles are on your Blazer? Its a common problem and is something to take seriously.

 

Had a simular with my 95. Mine turned out to be a cracked head.
They can get real thin between the valves.
Pulled them had them welded valve grind and a couple of new seats-runs like a champ now.

 

mine has 140k miles, got it from my neighbor, it didn't run and she didnt want it,i got it for free. it needed an ignition switch and new radiator. as of now thats all i thought it needed, but now needs an a/c compressor and dryer. and i need to find out where this f-ing coolant is going lol

 

yes my i have the same year mine started doing it at about 100k i replaced the heater core and it stoped maby try this also it might be your cooler lines that run to your transmission or my water pump failed be be for that i noticed to leaking from a bad gasket blazer are just junk cars save your money and buy somthing elce