Low A/C Rrefrigerant?
 

My A/C isn't as cold as before & I plugged in the manifold gauge, turned on the A/C & checked the pressure.


Low Side: 30 PSI
High Side: 135 PSI

Ambient Temperature: 75°F
Dash Vent Temperature: 22°C


Am I low with refrigerant?

Certainly a likely cause. First, make sure you have the wheel in the middle of the center vent set to all the way to the cold side (blue dots).

Here's a thread with useful info I found with the following google search hi and low gauge pressure ac e53 site:xoutpost.com

https://xoutpost.com/bmw-sav-forums/...ure-specs.html

See info in post #7 for example:

Once you get the gauges hooked up, the low side should be somewhere between 25 - 35 psi, and the high side somewhere between 200 - 300 psi, varies with environmental conditions as you know. Also, for example, if your aux fan stops working, the high side pressure can shoot up to 450 psi with a quickness. Its amazing what effect it has on the head pressure....

If the pressures are off, like the low side is 45 psi or higher, etc. Then there is likely a problem with an ac component and would need repairs. If its low, even just a hair low, then it probably has a leak somewhere. I'd bring it somewhere with an "automatic" ac machine. It essentially is set to recover, vacuum (which removes any moisture from the system) and fill to the proper charge level. No over or under filling with this setup, which is highly recommended with a vehicle so temperamental to its charge level as one that takes just a smidge under a pound... even an experienced indy with his gauges and a can hanging off of them can't properly judge the correct amount on these

Personally, I've had success with AC Pro from Walmart that comes with a simple gauge for the low side. I squeeze the trigger for about 5 seconds and then check the temp at the center vent with an infrared gun. Repeat that until it gets to about 45 F. The gauge on the AC Pro gets to about two-thirds of the green zone at this point. That may vary with the outside temperature. I usually fill it when it's between 80 and 90 F here.

https://www.walmart.com/ip/A-C-Pro-A...0-oz/353326131

I have to add some each spring. Used to be every other year and now it's every year. Mine is 19 years old and rubber gets dried out in the southwest.

Thanks for your comment!


I decided to give a try today & filled about 2.4oz.


Low Side: 30 PSI
High Side: 190 PSI
Ambient Temperature: 79°F
Dash Vent Temperature: 2°C


I think it works for now unless there is a leak somewhere & need to load some dye.

Any slow small leak is usually the valve stem cores. Super easy to replace and cheap. The problem is having to evacuate the entire systems to do it. A tool to replace large cores without evacuating R134a is not available. I have a small core removal tool.

Glad it helped!

You probably know more than me about this: I've heard you don't want to get too close to freezing out of the vents. The system will stop working. That's why I stop in the mid-forties F. That's cold enough to be effective on 100 F days :thumbup:

FWIW, these can be helpful: https://www.amazon.com/Dorman-902025.../dp/B0181H05LM

They don't always work, but...

:yourock:
Thanks! You guys are so helpful!

As Spock would say: "fascinating". :bustingup

I'll have order a few of those to try.

Nice solution!

Are they a confirmed fit for the e53, Nick? All I see is reviews for GM products.

I see some people add an o-ring to make a better seal and some use blue thread locker. O-ring would be better, correct?