A/C Problem

[ba82]

I have searched and cannot find any helpful info. Any help is much appreciated.

2001 3.0 5spd
AC is not "cold", but is cooler than no AC (it works a little bit).
About a month ago I added a can of r134 because the pressure was a bit low. (This did not make the AC any cooler as far as I can tell)
-Got another can today, hooked it up, pressure was extremely high (deep in to the "Red")
-The motor RPM seemed to be fluctuating as if it was being loaded and unloaded so I went and revved it to 4k. After a few moments of this, some sort of white smoke or steam or gas came shooting out from underneath the car right behind the radiator, looks like near the AC compressor?
-I immediately shut the car off and went to inspect. Because of how the Smoke/gas/steam looked, I had assumed that the can of r134 had come un-hooked and then was damaged, causing the can to release its contents. (The purpose of explaining this is to describe what happened when the gas was released)
To my surprise, the can was intact, still hooked up to the low pressure valve, and still showing the same (high) pressure reading. When I looked underneath the car and around the motor, everything looked normal, but there was a small amount of an amber/orange color fluid that had collected on the skid plate.

What happened? Was this some sort of pressure release? Why did it all of a sudden release the pressure if I hadn’t added any of the new r134? (This would make sense if I had added any, but I didn’t, I just checked the pressure, which again, was very high). Why didnt the pressure drop if the system released a bunch of gas?

One last bit of background, I just drove 7 hrs from Newport Beach to Tucson the night before with no problems. This was the longest drive I have taken the car on (since I bought the car a few months back the most I have done is 1 hr) The reason I decided to check the pressure of the system was that the AC was not keeping up with the 100 degree heat of Tucson

[trapdoor]

Sounds like the system has excess moisture. This will cause all sorts of issues as water is less compressable than 134.

When I had my A/C serviced last year due to a similar issue, the guy doing it had to charge and unload the system 3 times to remove the moisture. The white smoke/steam is probably 134 being vented off from the blow-off valve due to over pressure.

What you need is to get your A/C recharged, and ask to have the system drawn down to a deep vacuum for 30 mins minimum - this will boil off the excess moisture in the system and also give an indication of leaks. If it checks OK, get the system refilled to the correct weight of gas. If it 'blows off' again, get them to re-do it, with another deep vacuum. You may also need a new 'dryer' to be fitted as this can become contaminated/damaged.

Best of luck.

[ba82]

Originally Posted by trapdoor

Sounds like the system has excess moisture. This will cause all sorts of issues as water is less compressable than 134.

When I had my A/C serviced last year due to a similar issue, the guy doing it had to charge and unload the system 3 times to remove the moisture. The white smoke/steam is probably 134 being vented off from the blow-off valve due to over pressure.

What you need is to get your A/C recharged, and ask to have the system drawn down to a deep vacuum for 30 mins minimum - this will boil off the excess moisture in the system and also give an indication of leaks. If it checks OK, get the system refilled to the correct weight of gas. If it 'blows off' again, get them to re-do it, with another deep vacuum. You may also need a new 'dryer' to be fitted as this can become contaminated/damaged.

Best of luck.

Took it to a shop, It was holding 3 times the normal pressure. They ran the vac for 45 min then recharged the system with .97lbs of r134a. They said its now blowing at 55 degrees which the tech says is "normal for BMW"

The system is now cold, but I feel like it should be colder. What is a "normal" temp?