[Jdeleon]

I noticed today that when my 2013 2.4 Kia Optima is under heavy acceleration the AC starts blowing hot air until I let off the accelerator. What could be causing this problem?

 

[Turbonut]

Quick question, does the air flow remain the same or is it diminished?

 

[Jdeleon]

It stays the same

 

[Turbonut]

My first thought, if it turns warm immediately a door must be activating to have the air pass across the heater core. If it were something to do with the a/c unit e.g. compressor/refrigerant, it wouldn't turn warm immediately. You can give that reasoning a try by shutting off the a/c when driving, but it will not turn warm immediately. Give it a try and see if different temp change or the same. The only problem I see with this is that on older cars there would be a vacuum problem, but the blend door is electric, so don't know how that could be activated.

I would also check the the A/C pressures to be certain they're up to snuff.
Best I can do right now

 

[KingFatty]

Here's something from another website. It talks about how the compressor is disabled when the pressure gets too high, which can happen during acceleration.

maybe you can spend $20 to get access to the pressure gauge that comes with those A/C recharge bottles? Don't pierce the bottle, just use the gauge connected to the dummy plug to prevent leaks (I think?), connect it to the A/C system and see what your A/C pressure is at. Monitor the pressure when you hit the gas or accelerate, and see if it goes into the red zone.



Here is the quote, but note there is a slight difference in I believe this car used an A/C compressor with a clutch, unlike our Kias I believe that do not have an A/C clutch:

when I rev the engine,the pressures increase and that is when the compressor cycles off,one the pressures start to drop the compressor cycles back on. The pressures it cuts off at are 40 low side and 150 high side. Everytime I rev it and the gauges hit those pressures the compressor cycles off. I looked around and I can not find a high pressure switch,I do however have a pressure switch on the condenser,im assuming its the low pressure switch for when I unplug it the compressor instantly shuts off

 

[trefilov22]

I have this problem when my vehicle is at idle....

 

[charlie460]

How "heavy" are we talking? It is common for cars to turn off the A/C compressor at WOT on purpose.

 

[Dakinrin]

I have this problem when my vehicle is at idle....

Same with me. Did you fix this issue?