I owned my 2012 honda civic since its new and never charge the system and the last couple years the a/c doesn’t feel as cold.
I checked the the static pressure with the cold engine and outside temp of 57f. The manifold gauges shows 65 psi for both high and low. which is a bit higher than what is should read, it should roughly corresponded with outside temp . With the engine idle with a/c on high, I was get 7psi on low and 95ish on high. Even with engine rpm at around 1500, low was about below 5psi and high was bare above 100psi.
From what I read, I might have air in the system and also low on refrigerant.
Am I correct?
If so what cause the air get into a seal a/c system.
Do I just need to evac the line, pull a vacuum and recharge it to the AC label amount(i think its about 14oz of refrigerant.
If there is a leak in the system, I would like to fix it first. But if I have a leak, my static pressure should be lower instead of higher than normal pressure???
The static pressure is little high. But I wouldn’t worry about that.
The operating pressures though indicate there’s a problem with the expansion valve.
If the system has always had positive pressure, then air did not get into the system. It may have leaked a little but your static pressure doesn’t seem to indicate that. I think that @Tester is right but there is one other possibility and that would be deteriorating seals on the blend doors or the blend doors out of sync with the controller.
I don’t think your year honda uses the heater control valve anymore. Earlier Honda’s used them and they were very problematic. I think 97 was the last year for them though.
The static pressure will be about the same as full if the system has only 8 to 10 ounces of refrigerant.
A half-empty can of refrigerant has the same pressure as a full can, the pressure is relative to the chemicals boiling point and temperature.
Here is an updated:
I have to correct myself. I didn’t allow my a/c system to warm up before reading the gauges. This time, I was getting 15 psi on LP and 95psi HP. Based on this diagnostic, either its low on refrigerant, clogged expansion valve or high side blockage. The recovery rate when the compressor cycle off and on seems normal, so I’m assuming its just low on refrigerant.
End up just topping off the system with about 9.5oz (system takes 14.5 oz) and my a/c is back to normal again. But just wondering if its normal with age of the car, the refrigerant leak out from the compressor seals or the LP and HP valve? Should I put some dye and look for leaks or just wait
I use a refrigerant sniffer to locate AC leaks.
These are very sensitive to where they can locate leaks down to 1/2 oz per year, and can detect leaks in hard to see components, such as evaporators.
But if you have the time, the dye works too.