[jps328x91]

Hi Gang,

I have an interesting issue with my e91. It's a 2011 328 xdrive wagon. I have had it since the beginning of 2022. Now that it's getting warm out, I'm noticing that the air conditioner will only blow cold air if I have the fan speed set to one of the lower settings. As soon as I turn the air speed (volume) up, the air coming out of the vents is no longer cold. As soon as I turn it back down, it's cold again. The Blue/Red wheel is set to Blue.



Any ideas?

[Serf27]

It is low on Freon.

[Mike K]

My 2011 e91 likes an AC recharge every 2-3 years. Sometime when freon is low it will groan a bit through the vents.

[jps328x91]

Originally Posted by Serf27

It is low on Freon.

I topped it off. I THINK I got it to the correct psi, but it only helped. It did not fix it.

[Serf27]

If it is not the correct PSI, it may still not work properly. A gauge set is very cheap on Amazon.
If you are still needing to add Freon to Keep the cold blowing out, you have a leak somewhere.

[Mike K]

Did you do a full evac and recharge? That’s what mine needed...

[jps328x91]

Originally Posted by Serf27

If it is not the correct PSI, it may still not work properly. A gauge set is very cheap on Amazon.
If you are still needing to add Freon to Lee the cold blowing out, you have a leak somewhere.

Thank you for this.
Do you happen to know the correct PSI?

[Serf27]

I used this chart when I filled my system up.

And I used this gauge set and the pump to pull a vacuum.
ORION MOTOR TECH AC Gauge, AC Manifold Gauge Set for R134a R12 R22 R502, 3 Way Automotive AC Gauge Set with Antishock Gauges Hoses Couplers & Adapter, Puncturing Can Tap Freon Recharge Kit for HVAC https://www.amazon.com/dp/B019W5LIVS...ing=UTF8&psc=1

GYZJ 3.5 CFM Rotary Vane Vacuum Pump for HVAC/AC Refrigerant Recharging, Single Stage,1/4HP, 1/4" Flare, for Wine Degassing, Food Processing W/200ml Free Oil https://www.amazon.com/dp/B08B8NSKHV...ing=UTF8&psc=1

[jps328x91]

Originally Posted by Serf27

I used this chart when I filled my system up.

And I used this gauge set and the pump to pull a vacuum.
ORION MOTOR TECH AC Gauge, AC Manifold Gauge Set for R134a R12 R22 R502, 3 Way Automotive AC Gauge Set with Antishock Gauges Hoses Couplers & Adapter, Puncturing Can Tap Freon Recharge Kit for HVAC https://www.amazon.com/dp/B019W5LIVS...ing=UTF8&psc=1

GYZJ 3.5 CFM Rotary Vane Vacuum Pump for HVAC/AC Refrigerant Recharging, Single Stage,1/4HP, 1/4" Flare, for Wine Degassing, Food Processing W/200ml Free Oil https://www.amazon.com/dp/B08B8NSKHV...ing=UTF8&psc=1

Thank you for all of this. Is there any info/instructions on the process of evacuating the system using the pump?

[gbalthrop]

Originally Posted by jps328x91

... Is there any info/instructions on the process of evacuating the system using the pump?

I'm NOT a big Video Fan, but the YouTube video below explains and SHOWS how to use Manifold Gauges, a Vacuum Pump, and a Can Tap to add R-134a:

Several things to note:
1) R-134a in 12-oz. cans can be obtained from Walmart (SuperTech) for $9/can. Prices have risen by 2x+ in last year or two due to R-134a phase-out.
2) Charging by weight (with fully-evacuated system) is preferable, and the spec. is 20.8 Ounces total charge, or ONE full can & ~ 73% of 2nd can.
3) You CAN charge by Ambient Temp and Manifold Gauge Readings (just stop adding refrigerant BEFORE High Side gets to chart value high end. A little LOW on Refrigerant is better than Too MUCH.
4) If you have an Air Compressor with LARGE Tank (20+ Gallon Tank) you can use a ~$15 Air Vacuum Pump. It won't pull as low a vacuum as a electric-motor-driven pump, but I have used that Compressor-Driven vacuum pump to pump out a number of old Jag systems after changing hoses or O-rings.
5) Getting air & water vapor pumped out is essential BOTH to system health (preventing acid/corrosion inside lines & Evaporator) and to proper cooling as air is NON-Condensible.
6) If the system was open to atmosphere for a day or more, you will need to replace the Desiccant in the "Dryer" in the Condenser. Somewhere around 2009, the Dryer Desiccant bottle was no longer separately available and you have to change the Condenser. Functioning Desiccant is NEEDED to absorb any water (corrosive) in the lines.
7) If you lost Refrigeration Oil (PAG Oil) due to a ruptured hose or major damage to a line or fitting (oily residue at leak site), OR you replaced a component such as Compressor or Condenser, you will probably need to add some refrigeration oil. Consult a refrigeration specialist.
8) If the "Equilibrium" Pressure (when both High & Low Sides SAME pressure after engine has NOT run for 2+ hours), has NOT fallen below ~20 PSIG, then although Refrigerant Pressure has been LOST to the point where little or no cooling, or compressor will NOT operate, there is still little or no air in system, and simply recharging using 12-oz Can-Tap and Manifold Gauge Set, $37 from Amazon, will allow you to charge to proper gauge pressure based upon ambient Temp, using Pressure/Temp Chart such as that linked below:
https://www.acprocold.com/faq/r-134a...ressure-chart/
https://www.amazon.com/OrionMotorTec...NsaWNrPXRydWU=

Please let us know how it goes,
George

[mainbearing]

OP should not need a vacuum pump if the system loses refrigerant under normal circumstances. I typically add a couple of ounces every few years and that is all the system needs.

I just added some months ago, and the system is cooling great. It had some groaning noises starting the AC and the noise is gone after adding refrigerant.