ok guys i recently lost heat in my blazer. hadnt needed it for a while so i didnt notice but last week it snowed and iced so i needed heat. lo and behold NO HEAT! needless to say i was thrilled. i read the last post on this and flushed my heater core, took the hose to the radiator off at the radiator and the other hose off where it comes thru the firewall and then put a section off garden hose on that pipe. i put a nozzle on the hose to get a smaller stream of water with more pressure and ran it thru both hoses, a little bit of coolant came out, most came out when i took the hose of the radiator, and then just water came out. i figured ok that was easy. reattached the hoses, put the coolant back in, i had drained the radiator past the level where it would come out so it wouldnt come out, and cranked it up. before i lost my heat it would take about 10 minutes or so to heat up good on cold mornings when i needed it so i let it run for about 15 minutes. it was the same as before, just barely warm, and its 45 degrees outside and my hand was wet so... go figure. anyone have any ideas cuz its goin down to the teens tonight and it has been and will be cold for a while so i could really use it.
any help would really be appreciated.

 

replace the heater core

 

really, really,REALLY, dont wanna do that. done it once, not eager to do it again. AT ALL!!!

 

I'm pretty sure you don't have to remove any radiator hoses. The two hoses going into the firewall are whatlead to the heater core. I was going to flush my core but I knew I need another one because it was leaking. It was a pain but well worth it. Now try flushing the to tubes going to the heater core and see if that works.

oh... is your engine heating up to the correct temp?

 

ok i took some picks but every time i upload them nothing happens. so ill try and explain. the left and larger diameter hose runs to the radiator. the right and smaller diameter hose runs to the engine. the larger hose connects about halfway up the radiator. the smaller connects on the top back of the enginenear the transmission fluid dipstick.
as far as the engine temp goes my guage is either broken or my engine is exceptionally cool. the needle barely raises after an hour and a half of driving. im inclined to think theguage or thermostatis broken as i dont think this is normal. still it gave me heat a couple months ago the last time i used it and i havent done anything but changed the front brakes and rotors. go figure

 

Ok, first off, to just blindly recommend changing the heater core is wrong. Sorry...

After driving for 10-15 minutes, your engine should be up to full operating temperature. After driving, how hot is the upper radiator hose? If you haven't checked it, then please do. It is possible that your t-stat has failed open and it isn't allowing your engine to come up to temp. It is just allowing the coolant to circulate and because it is so cold outside, it is staying very cool.

Anytime something is amiss with a cooling system, I recommend that the t-stat and radiator cap be changed. The Stant super stat and Stant safety cap come out to be roughly $18 total and both the stat and cap are crucial parts in the cooling system.

Now, when you flushed your heater core, did water flow through it good? Since you didn't remove both of the hoses, you really don't know if any junk floated out or if the coolant was a crappy color when it came out of the core...

Good luck and let us know how things go.

*EDIT* Oh and have a look at the Image Posting link in my signature for details on posting images...

 

thanks for the advice ill try that. and i took both hoses off just at different places, when i took the short oneof at the firewall i put a section of waterhose on it and drained it into a bucket over the side. same with the other minus the waterhose since the hose was already long enough.

 

Oh ok, I missed that part. How did the fluid look when it was coming out of the drain hose?

 

ok when the fluid came out the drain hose there was very little coolant in it, it was mostly water. when i took the larger hose off at the radiator coolant came out. before i did anything i drained the radiator below the level of the larger hose. if that makes a difference. i just went out and ran it for about 15minutes. the top hose coming off the radiator was warm. both hoses coming off the heater core were warmer still. i dont know what you can make of that other coolant is circulating.
thanks for all the help so far.

 

Sounds like the thermostat is stuck open. It will allow the coolant to circulate, but never get hot. Your temp guage should be around 195 or so. If the guage is moving at all, I dont think its broke. Could be a loose wire. However, I recommend you replace the thermostat and the radiator cap. Mine cost me less then $15 for both and took almost 20 minutes. 15 of which was drinking a beer and farting around with the throttle bracket I needed to move.

My temp was around 150, changed the thermostat and rad cap and my temp went up to 195, and the heat will cook you out of the cab. The high today was 20, minus the windchill. I leave my HVAC temp setting on halfway and the 1st or 2nd fan speed.

By the way, if your getting fluid out of both the hoses on the firewall, your heater core is not plugged.