)n 2004 gmc why does the A/c blow hot air once in awhile . You can shut the engine off. Start up a little later and it is ok.

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Hello James

How are you doing? There are few reasons why the a/c fails. One is the the thermostat can be failing that's why it blows hot air. Another thing is that the expansion valve can be worn out. Is there any history of a/c cleaning and parts replacement? You may try to remove the negative battery connector as well and let it sit for 10 minutes or more to perform a system reset. There are times that the car's computer may fail which can cause a/c failure. I'll be standing by for your response.

Thank you and have a great day!

Relly

I see... Based on my experience and our clients. Evaporator cleaning, thermostat and expansion valve replacement resolves the issue. It's best to change the compressor oil and freon as well. Once it's done you'll be good.

Yes James I'm sure... I used to have a 10 year old car that fails to cool specially when it's park under the sun. Then I realized that it requires a/c cleaning and internal replacement like the expansion valve and thermostat. After that, no more a/c problem.

Is there anything else I can add or help you with James?

May I ask the exact model of your 2004 gmc?

In my estimate it will take $73 for thermostat, expansion valve and dryer. They will surely have an additional charge for the labor, compressor oil and evaporator cleaning.

Let me check if I can see how much they charge on freon and compressor oil James

$100 for freon charge and $20 for oil. Add another $100 for the labor. It's gonna be $293 on my estimate James

Dear James, It was a pleasure helping you with your GMC issue today. Here is a summary of the resolution.

Issue identified : Intermittent AC issue
Solution Implemented : Provided procedure on how to resolve AC issue. Provided estimate of repair. Solution Accepted
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