Automotive Air Conditioning Information Forum

2011 Audi A3 and in 104°f temps with vehicle off the low side won’t equalize with the high side. Low side show 105psi and high side 145. Shouldn’t my blue gauge be reading in the “retard” area?

Actually, no. The numbers you gave are not that far off. You won’t necessarily get perfect equalization.
If your system blows cold, leave it alone, please

That’s the thing, I forgot to mention that it’s not blowing cold and the compressor isn’t engaging. Why would the pressures not be equal? Retard is on the opposite side of the gauge than where inHG is for pulling vaccum. Gauge only reads to 130psi and then goes into retard~350psi. The system is off and this hot weather the saturation of r134a should be 140 which the high side is, therefore the low should be way past 105 and into the retard area.

Go to a pro-shop, better if a MACS certified, and have the system recovered, evacuated, and recharged with the correct amount of 134, and go from there. Right now you need to forget pressures.
The RRR I just mentioned will account for any seasonal losses and be a starting point for diagnosis

Fwiw, my sides don't always equalize either even on a well working system. Not a much as I am reading that you're are different though.

I also do not understand what you are saying about your gauge ranges and indicated readings. A picture of your gauge showing this condition might be helpful.

How long has it been sitting when you notice this inequality?

I can understand you wanting to understand it. And though recover and accurate refill may end up being the solution , it's interesting to see and understand what seems like oddball behavior, especially for thoae with a DIY mind.

Not sure I can agree with above poster.
He wants it to work, not a science experiment.
We are not aware of his skillsets, so RRR is still the best choice.
And as stated by a pro here, the unequal pressure when off are NOT unusual.

I have a 2015 A5 that uses r134a and I've noticed that it takes a long time to equalize. 30-45 minutes at the very least after engine was running. To the OP, I'd leave it off overnight then check pressures next day. Also always test your equipment. Try your gauges on another car and confirm that they are accurate. A scan tool with Audi/VW software (or VCDS) would be very helpful in diagnosis. You can read your evaporator temperature, high pressure sensor, refrigerant valve current, compressor torque data, refrigerant temperature, climate control status, fault codes, etc. Very common issue on these cars with Sanden PXE16 compressors is a faulty/contaminated refrigerant valve.