A/C not blowing cold

JFIGGINS

MEMBER
2005 AUDI A4
2.0L
4 CYL
TURBO
4WD
MANUAL
130,000 MILES

Just bought my first Audi, and the A/C sorta blows cold, but not really. Decided to pick up a set of gauges from Amazon to see exactly what was wrong. Here is what I found:

Car off on low pressure side - ~70psi

Car off pressure on high pressure side - 90psi

Car on no a/c low side - 100psi

Car on no a/c high side - 100psi

Car on with compressor running low side - 80psi

Car on with compressor running high side - 120psi

Any idea on what exactly is wrong? Condenser from the outside doesn't look clogged, and the fan is turning on and off when the AC is turned on and off, but I was reading that the low side should be around 30-40psi with the compressor on and 200 for the high side. Is that correct?

Car listed above is a 2005.5.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,709 POSTS

Welcome to 2CarPros.

First, the pressures will change based on outside temperatures. Can you tell me approximately what the temperature was when you checked?

Next, the 80 on the low side is way too high. The low side pressure will increase based on temperature, but even at 110°F it shouldn't be above 55. Unless the outside temperature was 200 degrees, we have an issue. LOL

On the flip side of things, 120 psi on the high side is too low unless it was approximately 40°f when checked

What does this all mean? well I would like to first start with having the system serviced. It should be evacuated and recharged to determine if things change. Here is a link that shows how it's done:

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

If that doesn't change anything, I suspect the compressor itself is bad.

Let me know what you find or if you have other questions. If you need directions for compressor replacement, let me know.

Take care,
Joe