i had great heat before i parked my blazer for the winter now i flushed my coolent for some reason im not getting any heat its like luke warm i wouldnt even say that. so im kinda thinking its the thermostat but i could be wrong thats why im asking before i just go and fix something that is not broken, the reason im saying it might be the thermostat is because the top hose on the radiator barely has any pressure to it even after 15 minutes of the truck being started its warm both of the hoses that come off the heater core are barley warm to, like it just seems like the thermostat is stuck open doesnt seem right to me

 

could be stuck open forsure. have you tried taking the thermostat housing off and looking at it?

 

Yep thats what it sounds like, stuck open. If it was stuck closed you would overheat, low fluid, the same. Only other thing would be partly clogged heater core, but do the cheaper stuff first. Actually while its cold if you take the radiator cap off and start it you will see flow through the radiator if its stuck open

 

well i havent took the thermostat housing off yet i will do that this weekend but i only used a jug of coolent for the whole project seems like i would use more than that i put the rest in the overflow container, it has coolent in all the lines so i wasnt worried about that at least its getting fluid i was scared it might be the water pump to but i didnt hear any strange noises so i might have to rule that out.

 

heck if it was the water pump it would be over heating.

 

yeah thats what i was thinking something didnt seem right specially with the radiator just taking one jug of coolent i was waiting for the coolent to bubble down it went down i added maybe 1/4 more of the second jug then i couldnt add anymore so i just added the rest in the overflow jug.

 

That could be it also, if you put to much in it will spit some out till level

 

well how much coolent does it take to completely fill the system? i just thought it would take at least a jug and half to fill it up again should i flush the heatercore?

 

Not sure, but I believe there is a hot and cold mark on the jug

 

If it were me I would replace the thermostat and the rad cap. Then I would properly burp the system by raising the front end, either by using a jack or parking on a hill, and run it with the rad cap off until the thermostat is fully open and all the air has bubbled out of it, topping up as you go.

It is so much easier to burp the system if the rad cap is the highest point in the system otherwise it is very easy to get an airlock.