AC stops working after driving over an hour on highway

[jlchavezz1]

I've tried searching the topic but came out empty handed. As the title says I've been traveling a lot lately with my 2004 Lincoln LS 3.9 (4 hours plus trips) and I noticed that after about an hour of driving with the AC on low and driving speeds about 70mph it stops sending air at all. I've had to raise it all the way up and with this barely any air comes out which is slightly cold. I have had to turn the AC off for about 10 minutes and air eventually comes out but not as cold as usual and not as strong. And it does make a swirling sound as the air comes out. I have stopped to eat and left the car off for about an hour and that way the air comes back to normal, yet after another hour or so I come up with the same issue that the air stops drastically. Anyone with the similar problem? I would like to know what is causing the issue, wouldn't want to get the whole AC replaced. Thanks.

 

[joegr]

Your evaporator is freezing over. Apparently your evap temperature sensor isn't working correctly. Replace it and that should solve the problem. Also have your refrigerant level checked. When it is a little low, it is more likely to freeze up the evaporator.

Failure of the evap temperature sensor is not frequent, but it is reported every now and then.

 

[jlchavezz1]

Thanks. Also, I get another problem with the AC that I think may be related. If I have my AC on and I turn it off, after minutes of having it on, I get a sound coming from the AC that immediately goes away if I turn on the AC again

 

[joegr]

Thanks. Also, I get another problem with the AC that I think may be related. If I have my AC on and I turn it off, after minutes of having it on, I get a sound coming from the AC that immediately goes away if I turn on the AC again

1. Pressure equalizing through the expansion valve. Normally, you don't hear it, so your refrigerant may be a little low.

- or -

2. Electric servos moving the air doors around. This is normal and expected.