Air Cond icing up
 

Hi Guys I have a problem that keeps happening whenever we go on a trip. I will define this by calling a trip longer than 3 hours driving. The air works faultlessly at all other times. It seems that the system is icing up because the fan is still working but no air is coming out of any of the air vents. Are there any fix's for this problem.

Thanks

Check the high side and low side pressure, Your low side pressure could be too low causing the evaporator to ice up.

thanks I will have to google that, I dont know what you mean but thanks for the tip

The other component is the expansion valve, but the system needs to have the refrigerant removed in order to replace it.

Are you running with the air recirculation on? It's the button on top of the ac button.

Does anyone know how much is the low and high pressure is supposed to be?

I think I have a similar problem. On longer trips, the AC is blowing warm air at times. Also, I can feel the compressor turn on and off and I would like to check the pressures. Thanks.

Check for evidence of leaks (oily residue) where the system pipes connect to the condenser and compressor. It is not unusual for the O-rings in those fittings to deteriorate. An inadequate refrigerant charge will cause the evaporator to be "super-cooled", resulting in the ice up condition.

2002 X5 3.0 236,000 miles
2004 325i 105,000 miles

the fan is working but no air is coming out... this is an actual symptom... the statement that it "ices up" - is it a fact that you observed or a specualtion, that you "think" might be happening?

the reason i am asking, if you observed the ice, than the suggestions provided are correct, if you did not observe the ice but suspect that is what causing the issue, than we should see why the air is not coming

Thanks for the pdf ABLE. I will look through it.
Terminator, you are right. I did not see the ice building up, and not wanting to start a new thread, I just "tacked" onto this one.

This has only happened on a long trip we took, after about 1 hr of driving.
It doesn't happen while driving in the city.

And in my case, air still comes out of the vents, it's just not that cold. I had to keep on 60 for it to be semi-cold. After I turned off the compressor for about 1 minute, the AC came back on. Even then I could feel it go "in and out". Not sure if that's normal on long trips.