'99 blazer no heat

so my mom has a 99 blazer with about 45,000 miles. when she turn the heat on in the car it blows hot air for a minute or two then it just blows cold air. our neighbor/family friend is a mechanic at an acura dealership. his good friend is a mechanic at a chevy dealership so our neighbor took the car to him at the chevy place hopingwe wouldnt get the shaft. they had the car all day. he brought the car back later that night and said they didnt fix anything. they said there was a clog in the system somewhere that wasnt allowing enough coolant through to make the air hot enough fast enough. this part makes sense to me. if theheater core is not getting enough coolant circualted through it, then there wont be enough heat to actually warm up the cold air. anyways, they said they want to flusk the coolant, fill it with some type of solution to "disolve" the clog" which they say takes overnight, then they would reflush it and fill with coolant. they gave an estimate of about $450:banghead:

my questions are...

is here really something they can put in there to "disolve" the clog?

if the disolver exists, can it harm gaskets, seals etc... if not done correctly or left in too long...

and finally, if the stuff does exist, is it available to the public so that i can do it myself, or is it a dealer only type of product. i'd like to save my mom same $$$ if i can

thanks for any help

this heater core restiction is common ...you simply remove the engine hoses at the engine that go to the heater core ..using a garden hose low pressure at first you apply water pressure then reverse connections until the water flows thru the core freely..after it looks good use of air pressure to blow out the core gets it better..since you have some flow it should be workable with out chemicals flush....acid is the flush material. after you use this you must completely drain the entire coolant system and flush with a baking soda water mix to neutralize the acid , before continuing with the coolant ..

use distilled water and dexcool if dexcool was used before..mixing of dexcool with other coolants is a reason this could have occured...

dont be fooled by compatible coolants..if its dexcool approved it with have the GM logo on it ...also use distilled water ..minerals in tap water/well water eat at the metal thru electrical conduction...

Don't be afraid to repeat the backflushing process. Be gentle with the air pressure as well. The cooling system is only rated for 15 psi so you don't need to get real crazy. Flushing with hot water can also help. I have spent 15 minutes to get some clean and others a couple of hours. It will make a huge mess!

thanks for the input guys. the blazer came with dex from the factory so thats what i'll put back in. i'll give it a shot this weekend hopefully and post how it turns out. tha nks again for the help.

rich

Hey Bass Caster, read this thread it will answer a lot of your questions:

http://www.automotiveforums.com/vbulletin/showthread.php?t=729213

Hey Bass Caster, read this thread it will answer a lot of your questions:

http://www.automotiveforums.com/vbulletin/showthread.php?t=729213

this dexcool attack in your suggested thread is pure B/S


" Dex-Cool® Antifreeze. - There are volumes of information on the Internet regarding Dex-Cool® Antifreeze which I will not re-hash here. The advertised claim that it will last 5 years or 150,000 miles is historically the exception rather than the rule in most vehicles. Air in the system and/or poor maintenance will cause the Dex-Cool® to turn highly acidic and start eating away at the engine and/or cooling system components, resulting in inevitable failure. There are test strips available on the Internet to check the Acidity level in your system. Keeping your system clean and topped off is an absolute must with Dex-Cool®. If you do not flush this stuff out and replace it every year or two max, you will in all likelihood run into very expensive repairs including replacement of the Intake Manifold gaskets, Head gaskets, Radiators, and/or Water Pumps etc. General Motors still recommends that vehicles that came with Dex-Cool® originally should continue to use Dex-Cool® as replacement or for topping off. GM continues to stand behind Dex-Cool®, claiming neglect and contamination is the real culprit. Prestone makes antifreeze that is yellow in color that is reported to safely replace Dex-Cool®. "

dexcool with the GM logo is the only dexcool to use ...compatible coolants are what get owners into trouble as well as lube JOCKIES topping off with non dexcool...I have used this product since 1996 well over 100,000mi and with distilled water and 60% dexcool I have had none of the bad stories many have faced blaming the coolant..

replacing the coolant every 3-4years is needed..this should ensure that the system works correctly...flushing the heater core in any coolant type vehicle is needed at every coolant replacement interval...

prestone yellow coolant is not dexcool !!!!! this is the silicone based product that very quickly will destroy a dexcool system....

...I have used this product since 1996 well over 100,000mi and with distilled water and 60% dexcool I have had none of the bad stories many have faced blaming the coolant..

I am happy for you. However, you are the exception rather than the rule. That is why GM is being sued over Dexcool. Let's not trash this guy's thread. Nuff Said.

I am happy for you. However, you are the exception rather than the rule. That is why GM is being sued over Dexcool. Let's not trash this guy's thread. Nuff Said.

I believe GM should be sued because of the dexcool coolant...
this is because GM did not properly warn owners, that use of dexcool with other coolants, and non distilled water will DAMAGE THE COOLANT SYSTEM.

I as mentioned before don't agree with his findings with the proper handling of dexcool...or its performance.

I am an exception because I did my research on this in the 1990's..I find it hard to believe some still don't get it...

most know what I have practiced since the 1990's , today..It's
to bad, many though are allowing their coolant system, to be destroyed.

By the time you get this all flushed out and working properly I almost guarantee you will have needed to change the rad, heatercore and intake gaskets. Happened to me and lots of these trucks that I have worked on. Once they are gummed up, flushing them just brings on a world of pain.

PS: Good or bad, Dexcool belongs in these engines.