AC only blows cold air when your driving?

[B8-A4]

Ive been having this issue on and off with my AC, and when your sitting not driving it gets warm, then when you start to drive it cools down again. Whats your thoughts on this?

[Evopro54]

x2 same with my 2012, only cold when in motion.

[dscline]

First thing I would do is check to make sure your radiator fan is working when the car is idling with the AC on.

[WngoA4]

I have the same issue with my 2012.

[AudiHockey]

My 09 blows cold air while in motion and not in motion

[ECS Tuning-Audi]

Could be that the condenser is not getting enough air flow. As others have said start with checking to see if your secondary fan is coming on when the AC is activated.

Jason

[bluetori]

Well shit.....

[B8-A4]

not really sure how much help that is :-),

all my fans are working correctly when they should.

just something else ill have audi look at when they tear my motor apart for new pistons and rings.

My 09 blows cold air while in motion and not in motion

[ECS Tuning-Audi]

Might want to throw a set of gauges on the AC system and check your high and low pressure too. If you know a friend with a shop that services AC they should have them.

Jason

[Celiot29]

I have always thought this was just a product of getting no airflow while stopped as I have had this in both my 09 and 13" a4 it's still cold when stopped just not nearly as cold as when in motion

[TCHUN003]

Well my ac just doesn't blow cold air period...

[b4a41point8t]

This is a bit confusing. Do you mean it blows LESS cold when not moving or NOT cold at all. Obviously it will blow less cold when the engine is at idle. That's every car, its belt driven.

[dscline]

Obviously it will blow less cold when the engine is at idle. That's every car, its belt driven.

Not necessarily, it just depends on whether it is designed with sufficient capacity. They use variable displacement compressors that are constantly adjusting how much they pump per revolution, based on the cooling requirements. When the engine is at idle, the compressor will be turning slower, but it could still be pumping as much via increased stroke. Though if you've swapped out to a smaller crank pulley, I could see the capacity being reduced enough that it couldn't keep up at idle, even at max stroke. Even before variable displacement compressors became commonplace, the compressors would cycle based on suction pressure/temperature, so they could still maintain capacity at idle, IF it was sized sufficiently.

With that said, I have noticed on my B8 that it typically goes through an odd period in the afternoon when I leave work on a hot day... when I come to a stop light shortly after leaving work, it goes through a brief period where it feels as if the AC has been switched off briefly, then back on. I've posted about it here. But that seems to be a brief one-time occurrence per cold start, it resumes normal cooling after that, even while still being at a stop.