AC low side really high pressure?

[K20FA5]

My kids Kia is blowing warm air. It gets a little cooler, not cold, at highway speeds. When I had the front end up on ramps during the last oil change it was blowing cold like that?

I bought a 1234yf recharge kit and when I put it on the low pressure side with the AC on max, I’m reading between 97 and 100 psi on the digital gauge it came with. It’s an AC Avalanche recharge kit. The ambient temp when I did this was right about 100 degrees.

Am I looking at a bad thermal expansion valve?

 

[Astro14]

Let me preface this by saying I don’t know Kia well.

I know that in other car makes, a system fault will prevent the compressor from engaging. Because you’re only looking at the low side, and don’t know what the high side is, I have to wonder if the compressor is running.

Again in other makes with which I’m familiar, you’ll need the diagnostic software to turn the compressor on to be able to charge the system.

I don’t know if that applies to your Kia. But it wouldn’t surprise me.

Maybe take a look on the Kia forum and see if that’s how it works

 

[Oro_O]

…. Because you’re only looking at the low side, and don’t know what the high side is, I have to wonder if the compressor is running.

….

This was my first thought. He has already given steps.

I would add that you can get a proper manifold gauge set to read both sides loaned for free from any auto parts store. This will help quite a lot.

 

[K20FA5]

Thanks Astro14. The compressor wasn’t coming on. I pulled it up on ramps, and the compressor would come on. I filled up the low side to 50psi. It was at 30psi. 50-55psi is what the bottle said for 95+ temps. It immediately got cold. I drove it around and now it seems to be working like it should. I hope it holds!!!