QuestionHi,I got its 2001 Blazer.The fan working great but no hot
air.How can I fix it? I found one guy on the web that the
same thing happen to him.Answer was the GM's Dexcool has not
been very long lasting,especially with Blazers.The coolant turns into mud and clogs the heater core. Have you herd of
this before?Thanks for your help.
PS.88,000mi 6 cylinder automatic
James
AnswerHi James,
You pretty much answered your own question. Restricted heater cores have been a problem. I've serviced many clogged heater cores, especially on Caprice's and Impala's. There is a bulletin out that details the repair info. Sorry I cannot access the bulletin.
Taking into consideration that your coolant level is full and the thermostat is ok, engine is getting up to the proper temperature, it's most likely a clogged heater core.
I'm not a big fan of Dexcool. In my own cars, the first thing I do is get rid of the Dexcool.
Ok, you can try this: Get some prestone engine flush. It's an acid based cleaner that will eat through the clog. Follow instructions on the bottle.
After your done flushing the system remove the heater hose at the heater core. With a garden hose flush the heater through one way and then the other. Keep doing it until the water is clear and flows good.
Make sure you try to get as much of the acid out of the system as possible.
Refill cooling system with Prestone Extended Life Coolant 50/50 mix. It will say it can be used in all makes and all models. I prefer the 50/50 mix, you won't have to add water and the water that is in Presone is de-mineralized.
I'd also add 2 or 3 vegetable sealing tablets as a preventive measure. Don't reuse Dexcool.
I also suggest draining and refilling your coolant with the Prestone 50/50 every 2 years. Prestone is cheap...heater cores and radiators are not.
This job's not too hard but it can be time consuming. I would try this before replacing the heater core. If your system is real bad I would also replace the thermostat and radiator cap.
Hope this helps,
Robert
