Ok , I noticed my blazer was going low on coolant very quickly. I would fill it up and sometimes as fast a 3-4 days it would be pretty much empty again. When i was low on coolant the heat would only work when the truck was moving, of course. Well today I put some more coolant in it, but noticed the heat wasn't working at all. It won't get warm at all, but now the coolant isn't leaking.. or if it is it isn't leaking nearly as fast as it was. I don't know if the two problems are related but why isn't the heat working at all now if the leak has stopped/slowed? Sorry if the question is kind of stupid, the blazer is my first vehicle so i don't have any experience with any of this, YET. LOL

 

Some weeks ago I had a coolant leaking at the intake manifold near the coolant thermostat. Take a look, some say that is a typical Blazer problem.

 

You more than likely have air in your coolant hoses or core now blocking the flow of water and preventing the heater core from heating up. I would check all of my hoses and clamps and burp my radiator ( raise your front end on ramps and loosen radiator cap ( do when cold ) start your truck and add coolant as needed.) If all is well then as stated above, your lower intake manifold gaskets are probably leaking and need to be replaced.

 

Yeah, i'm going to do that. Today the heat started working again after letting it run for a little while, still no leak. I'm going to burp it just to make sure everything is cleared out though. Thanks guys!

 

well first off if your filling your coolant that much and its not leaking out onto the ground you have a bigger problem then no heat.
lower intake manifold leaks are common...if left alone it will cause major engine damage.
if i were you i would check my oil and spark plugs for coolant contamination. also find that leak. when my lower intake leaked i was lucky it leaked between the manifold and the valve covers so it was external leak.
if you do a search around here you will find alot of threads covering this. also a how to is around here to. the job can be done at home for about 100 (if it is lower intake leak)

good luck

 

My lower intake also leaked externally. I by chance found it by chance. It was leaking between in the corner on the front under the A/C compression.
But leaks I have had are heater hoses, water pump, not enough to start showing yet. heater core, with no coolant inside truck & radiator. It seemed that as I had one leak fixed another would appear. So look closely.

 

I personally think it's a hose. The truck sat for a log time before I bought it, I checked my oil and it's clean. Tomorrow after school I'm going to spend pretty much all day naking sure it is just a hose though. Yoh guys obviously know more than me so I will definitely take all of your advice. Thanks!

 

update: ok well It is dark as hell, bu i just dropped my girlfriend off at her house and this coolant problem has been bugging me so i decided to check. After doing some research on here i think I may have a blocked hose somewhere now. At first i was losing my coolant fast, but now the coolant has been at the same level for about a week. It is a muddy brown color in the tank. I wasn't able to check the level in the radiator because it was raining and i couldn't get the cap off fast enough. The temperature is running around 160-170ish. So anyone have any ideas on what it could be? I don't understand how i went from losing too much to now being worried about a blocked hose. but the brown coolant set off an alarm so i have no idea. lol

 

Dexcool antil freeze starts orange and I have heard if you mix any other type of antifreeze with it it turns muddy
I would suggest a complete flush of the reclaim tank and cooling system

 

Oh i see. ok, that is what I will be doing tonight. How long would that take?