Ahhhhh..... I guess you stand corrected. LOL. Yes, you still have a heater core. Its basically a mini-radiator that transfers heat from your cooling system into your 'cabin' by having air blow over it. Kind of like your radiator does for your engine but in reverse - if that makes since. It sounds as if you either have a partially functional thermostat or a reduced flow in your heater core circuit. My suggestion (for what its worth) would be to start with a new thermostat and radiator cap (cap because you were talking about your coolant bottle being empty) and see what happens. If that doesn't cure it, get your heater core system back flushed. You could do this yourself with a garden hose. And not to open a can of worms but if you have dex-cool... Well lets just say - to each their own. My truck came with dexcool, had issues, and will never have it again.

Good luck,

 

While you're doing the t-stat, I would strongly suggest that you be sure you fill the cooling system properly. Leaving air pockets in the cooling system will cause poor cooling problems. Also, I would strongly suggest you have the cooling system pressure tested. Be sure it's by somebody who will look for leaks from UNDER the vehicle too. There's a lot of time coolant will leak, but get burnt off on exhaust, etc. You will never see a drip on the ground.

If you wish, you can see this information about refilling your cooling system properly.

Hope this helps!

 

thanks guys!! thanks for the correction....I only thought about the heater core thing because I had an 87 subdance with about a million miles on it that the heater core fell out...yes it fell out....I had antifreeze going in my vehicle.....(there's a long story attached to exactly why it fell out....it wasn't because I was irresponisble removing a heater hose....no.....no way..) anyways I was almost positive they weren't in cars....well at least that they didn't work the same way........but then again..the last car was a kia....just a smidge different than a blazer.....I will hopefuly give it a tune up and once over this week.....thanks again you all for the help!!!!

 

odd that the heater core of your sundance fell out. it should've been wedged in place like this one from an '87 lebaron:
http://magtec.rvglug.org/misc/lebaro...re/newcore.jpg

are you sure it didn't just spring a leak?

 

no.....it didn't spring a leak......long story short...my heater hose sprung a leak....a clamp some gum...and a plastic bag help me make it back to class.....well in replacing the hose...seems simple huh??? not so much...I tried desperately to "gently" peel it off....that's what my dad told me...well I got pissed off because the hose was thouroughly stuck...I mean crazy stuck....so I pulled...and pushed..and banged..and yanked......hit it a few times......I put the new hose on....started it up....ran ok...started home with someone following me....well the whole time antifreeze had been pouring onto the passenger side floor....my radiator was pretty low when I cam back the next day..filled her up with water...left the cap loose...and crawled to the chevy dealership...who just bypassed the heatercore....it was enought to drive it home..and sell it for like 500 for parts.....it was a piece when we got it..fixed it up..made it about 60,000 more miles than we thought out of it.....so yes...it did actualy fall..well lets say crack....and not just a leak...(did I mention it was rusted out.....and the heat had been on the fritz for a while?)

 

Great reading. I somehow remember that there are water valves on many of today's automobiles. A valve operated by electronics, sitting in the heater hose path. Used to control the flow of water through the heater core. Keeps heater core from being HOT at all times, thus heating inside of car ALL the time. This is a possibility. Somehow simply failing to work and closed, at least partially.

Another good possibility is a vacuum hose to the control system for the heat, air and fan. Or may be known as the "climate control" system. Sometimes those hoses have a problem. The hoses control gates or if you want to think of them as "doors"/ valves, that direct airflow to and from the heater core and the rest of the ducting. If a gate doesnt move to allow air movement to or from the heater core to the fan and vents, then no heat will happen or too much in the summer.

In olden days, much of this was actually controlled by physical (metal) cables that actually opened "doors".



These are general terms/principles but apply to many of todays vehicles.

The trick becomes one of determining which of the two parts is actually failing. Divide an conquer.

If you can touch or feel the heater core and it DOES get hot, then look for a vacuum controlled venting/gating/door problem..