Heater Problem

I Have A 96 Chevy S-10 Blazer And When I Turn The Heater On It Blows But The Problem Is That It Only Blows Cold Air - No Heat. Can Some One Give Me Some Advice On The Problem Please. I am not getting any Steam coming from the vents no water on the floor board under the dash

when your engine is cooled down, check the level of your antifreeze in your rad, not your reservoir. If level is down fill it up, and then run the engine without the cap of a while to get any air bubbles trap in the system out. Feel that you hoses running to your heater core are getting hot, they should get hot enough that it is uncomfortable to hold them. If that is not it, then there is something wrong with the temperature control mechanism.

I Have A 96 Chevy S-10 Blazer And When I Turn The Heater On It Blows But The Problem Is That It Only Blows Cold Air - No Heat. Can Some One Give Me Some Advice On The Problem Please. I am not getting any Steam coming from the vents no water on the floor board under the dash

Go and get your cooling system reverse flushed and your coolant replaced if you have never done it.

Your heater core is plugged.

You can tell this by feeling both of the hoses going to the heater core through the engine bay.

One will be hot and the other cold or cool which means that coolant is not flowing through it.

Your heater core may not be plugged. TYHe heater core on the blazers is above the engine it is the highest point in the cooling sysyem. You probably have an air pocket in the system as described above. I've had this same problem for a while. Didn't know it because the weather was warm and I wasn't using the heater. Filled the system and bled the heater core by removing the hoses and filling the system from the top.

Unfortunatly this same problem happened again 1 wk later. Found out the intake gaskets were faulty. I removed the intake and changed the gaskets. Problem fixed :D. No more coolant loss, and always have heat.

Regards,
Heli

Had the same problem with my blazer.
As heli stated , the heater core is above the engine so it's difficullt to blead.I ended up parking it on a hill so the radiator core was even or below engine level and let it run with the cap off. Hope this helps.

The system is pressureized.

You don't have to bleed it.

Replace the rad cap with a new "NON ACDELCO: rad cap and it will force the air out of the system.

The system is pressureized.

You don't have to bleed it.

Replace the rad cap with a new "NON ACDELCO: rad cap and it will force the air out of the system.

Untrue... Air pockets can easily develop inside our engines. Try rebuilding an entire motor with nothing in it... You have to unplug the block (usually by the temp sensor) to bleed it out. New heater core will not automatically purge itself of air...Again, air pockets can develope.

Untrue... Air pockets can easily develop inside our engines. Try rebuilding an entire motor with nothing in it... You have to unplug the block (usually by the temp sensor) to bleed it out. New heater core will not automatically purge itself of air...Again, air pockets can develope.

My heater core had air in it caused by a defective stock Ac-Delco rad cap.

I reinstalled a new non ac-delco cap, filled up the overflow tank to its proper level and took it for a drive. When I got back, the tank was borderline empty. I refilled it a couple times and the system bled itself and filled up the heater core and I have never had a problem since.

Again, read my post, they CAN delvelop. The solution is not necessarily just replacing the cap. The stock caps are fine. Proper bleeding of the system is always needed for any system involving fluids. The only reason the fuel system doesn't need bled is because it's open at the throttlebody making self purging. (try bleeding out a diesel system oneday). Any enclosed system needs bleeding. (brakes, power steering, cooling, etc)

Again, read my post, they CAN delvelop. The solution is not necessarily just replacing the cap. The stock caps are fine. Proper bleeding of the system is always needed for any system involving fluids. The only reason the fuel system doesn't need bled is because it's open at the throttlebody making self purging. (try bleeding out a diesel system oneday). Any enclosed system needs bleeding. (brakes, power steering, cooling, etc)

AGAIN READ MY POST!

Seeing you are saying the stock caps are fine just shows you how much you know on this situation. The fibrous rubber gasket on the AC Delco cap is flawed and is know industry wide to cause the Dexcool Sludging problem due to allowing air into the system.

When you turn off the truck and it cools, it draws air into the rad instead of drawing in coolant from the tank.

Don't question what I friggin said because it isn't theory, I DID IT TO MY TRUCK! AND IT WORKED!

Here is an article if you need more proof:

http://www.imcool.com/articles/antifreeze-coolant/dexcool-macs2001.htm

AGAIN READ MY POST!

Seeing you are saying the stock caps are fine just shows you how much you know on this situation. The fibrous rubber gasket on the AC Delco cap is flawed and is know industry wide to cause the Dexcool Sludging problem due to allowing air into the system.

When you turn off the truck and it cools, it draws air into the rad instead of drawing in coolant from the tank.

Don't question what I friggin said because it isn't theory, I DID IT TO MY TRUCK! AND IT WORKED!

Here is an article if you need more proof:

http://www.imcool.com/articles/antifreeze-coolant/dexcool-macs2001.htmAgain, here I am looking for anything I missed in my 40 some odd years of building engines, big and small, and in between. The rule of thumb, and common knowledge in any repair shop worth it`s reputation, is that, for any reason should coolant be needed to bring the level in the radiator back to full in a pressurized system, the air, MUST, be bled off. Not via the expansion tank, but by actually bleeding the air from the block, and most importantly the heater core. The bleed procedure LT described will work, but while it`s working the heads and block are being cooled by air pockets that are trapped in the closed system. Too big of a risk to take, when proper bleeding is so easy, and quick. Remember the plastic tank you add fluid to is an expansion tank, not a recovery or over flow tank. As for the a/c cap being flawed, if so replace it w/ an aftermarket. BUT BLEED YOUR SYSTEM

It is a recovery tank and is where my rad draws in coolant when the system is cooling and retracting.

This is what is causing the many overheating and air pocket problems with the 15psi system we all have in our blazers.

The stock AC Delco cap has been known to have a poor fibrous rubber gasket that will fail and harden over time.

When this occurs, it will suck in air through the defective seal instead of recovery the coolant is needs during contraction.

This is where my problem with my Blazer was occuring 3 or so months ago. All that was required was a new cap (not from the dealer) and the system replenished itself.

Also, with a defective rad cap seal, 15psi pressure will not be maintained seeing the pressure is there to counteract the boiling point of the coolant.

With the pressure not being maintained, the coolants boiling point will dimish quite significantly and can often be seen as high than normal running temperatures over 210.

It is a recovery tank and is where my rad draws in coolant when the system is cooling and retracting.

This is what is causing the many overheating and air pocket problems with the 15psi system we all have in our blazers.

The stock AC Delco cap has been known to have a poor fibrous rubber gasket that will fail and harden over time.

When this occurs, it will suck in air through the defective seal instead of recovery the coolant is needs during contraction.

This is where my problem with my Blazer was occuring 3 or so months ago. All that was required was a new cap (not from the dealer) and the system replenished itself.

Also, with a defective rad cap seal, 15psi pressure will not be maintained seeing the pressure is there to counteract the boiling point of the coolant.

With the pressure not being maintained, the coolants boiling point will dimish quite significantly and can often be seen as high than normal running temperatures over 210.Hold on to your hat, here it comes !! I totally understand, and agree w/ your description on the workings of a pressurized system(never implied otherwise) my only issue is your re-fill procedure, it`s only correct in theory, not in practice. While your cooling system is waiting for the expansion tank to replenish the coolant, the entire system is left vulnerable. Manual bleeding, will in less time, avoid hot spots, or worse, heat cracks

Very true, I understand your theory and it is indeed perfectly correct.

I was just suggesting a way for the system to do it itself which in some cases can be the simplest and easiest way.

For minor things such as the gurgling heater core, the bleeding doesn't really need to be done, the cooling system will force the are out by displacement.

But that is only my way of doing things.

People have other methods which are perfectly fine too.

All is good.

If using straight water, the boiling point of the water with a 15 psi cap would be 249 or 250 degrees F. Just in case anyone was interested. And that is at sea level.

Ok sorry I hate to bring up an old post, but I now am experiencing this problem :mad: I had the radiator flushed about 3 weeks ago, getting ready for winter, at a jiffy lube (would have done it myself but I live in an apartment complex), to get it reversed flushed should I just go there and say I need to have this system reversed flushed? Don’t mean to sound dumb but I use to live in Florida now live in Illinois and I starting to desperately need the heat, oh and this just started today and yes the two hoses going into the heater core one is cold and the other is hot, but not hot enough that I can't hold it. Thanks to all

If you had the radiator flushed 3 weeks ago and one of the hoses is cold at the core, then they didn't do it correctly. Bring it back to where you got it done and demand it be done correctly.

Well, that was what i was planing to do, I just want to e better informed so that they don't try to pull their "B-S" on me I kept the receipt for this reason when i did it, and should i go there and ask them to reverse flush it while they are there or just for them to do it right this time? Thanks for the advice

Okay just for clarificaion purposes into the heater core there are two hoses one comes from the water pump to the heater and one from the heater to the the top of the intake manifold, is the correct flow?

Water pump---> Heater Core ---> Intake Manifold

or is it like this:

Intake Manifold ---> Heater Core ---> Water pump

i was thinking of fixing it myself instead of letting someone else touch my car again, should have never done that in the first place, D'oh

Thanks All

You need to ask them to flush it both ways.

Well I tried going back there, and they tried telling me that it was the termostat, or may be this that and the other, I even told them that they had to flush the system again, and they refused. so i got upset and i am going to call the corporate headquaters, and atempt to get my money back and i will just do it myself, yeah i know that it will take longer but at least i will know that i truly cleaned the system,

The really funny thing is that the kid that took the keys to my car did not even know how to turn it on!!!! (it is a manual trany press the clutch d'uh)
then the other jackass that got in the car could not get it to move because he did not realize that i had the parking brake on. then to release it he opened the hood 2 times, I mean seriously where the hell do they find these people????????????????

Oh and i mean NO offense to any of you who are mechanics or work at a place like this but seriously this is just ridiculus, I know that i do not know alot but i think that i know enough to realize what is going on with my car. any ways will update on the out come when i am finished dealing with these idiots...

They aren't mechanics, they are lube monkeys.

BIG difference.

Well as i had said i would post an update on the out come, I removed the bottom radiator hose and let everything drain out, and both heater hoses and stuck a water hose, and drained it both ways, and yes i refilled with it with dexcool.

Also to all those of you who changed from dexcool (orange) to the regular anti-freeze (green), do some more research on this change, so far it is my understanding that the newer systems are designed to work with dex-cool and the green stuff could actually cause other damage to engine parts, just food for thought...Good luck to all

Make sure you replace your rad cap with a cap not made by AC Delco.

Is it possible that it is blend door problem, not coolant?

Try doing this,reversing the heater hoses at the heater core.Found out this does work a lot

Guys please take a look at the dates before posting. This thread is 3 and a half years old. Thanks

Guys please take a look at the dates before posting. This thread is 3 and a half years old. Thanks
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