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Q: Heater blows cold on 2005 Chevrolet Malibu

The heater blows cold, the temperature gauge indicates the engine is warm. I've not flushed the coolant and have 100K + miles. would that fix the problem or is there something else I should do?
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Generally flushing the coolant will not help you with this problem, but with 100,000 miles, you could have a blocked heater core, which would cause this problem. It may also be an issue with the climate control system air flow controls. You will need to get it inspected to know what is causing the problem for sure.
Best of luck, let us know what you find!

That is a technician with the magical touch! Glad to hear it is fixed, at least temporarily. Can you do us a favor and please review the shop you took it to so other people in your area will know about the great service they provided you!

I decided to take it in to a local repair guy for diagnosis. He felt the main hose to see if thermostate was working and the two hoses to heater core. All were warm so everything was good there. He then turned the hot/cold knob several times listening for response. This action broke the door to the heater core free and it now works. No charge and it took about 3 minutes of his time.
Your reply to the answer given to your question is what helped me. I did what your repair guy did. It took a couple of days trying this technique and it finally worked! Thanks for the info. It saved us a huge headache and repair bill.

Little Sister
My 08dodge heater is not blowing hot now the ac is at first starts working.but it slows the flow of air to almost nothing.what would cause this to happen. I've checked the hoses an they r fine . both heat the same.and the check engine light came on ready a code of poo73 ambient air temperature sensor circuit high
What should I do.
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