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Help! My AC only cools when accelerating!

I have had this problem with my 99 Honda Civic for several years and I can’t take it anymore! The a/c works only when the car is accelerating. The fan is still blowing when I am at a stoplight or in a drive-thru, it just blows hot air. I’ve tried putting it in neutral and revving the engine while waiting to move again, but this does not seem to make a difference. Now that summer is in full-swing, I am at the end of my rope!

So, in the past several years have you had it checked by a mechanic? If so what has been done so far to try and fix it?

This problem can be caused from a malfunctioning expansion valve. This valve is what meters the amount of refrigerant that enters the evaporator as a gas. If this valve fails to go the proper position for refrigerant line temperature, it doesn’t convert the refrigerant into a gas, but instead it remains a liquid, and the cooling effect stops.

You need to take it to an AC shop so they can check and see if the expansion valve is working properly.


Last summer the compressor went out and my husband replaced it. This problem was there before and after the compressor change. Otherwise, this specific problem has not been checked.

How can you be at the end of your rope when you apparently haven’t tried to fix it yet?

Are you always this helpful?

People get so irritated when you make the smallest joke. We are free to add some levity to the Forum without being chastised aren’t we?

I was just adding a little levity myself…is that so wrong?

I fully agree it was not wrong for you to add some levity. I wish to stay on good terms with our customers. Don’t take me wrong but it seems people are so much on edge and very easily get irritated.