Izeloz

I have a 2009 Civic LX with an AC issue. The AC started causing a heavy drag on the motor at idle. Things got worse until the pressure relief valve started intermittently releasing refrigerant. The car wouldn't stay running with the AC on or off. I pulled the relay and the car ran fine (albeit without any AC). After some research I found that the OEM Omron relay was a common issue. I replaced the relay with the Mitsuba upgrade, charged the system to replace refrigerant lost to venting and, after not long at all, had the same problem happen. The idle would drop really low and the refrigerant would vent from the pressure relief valve. I verified that the AC clutch was engaging AND disengaging the way it should, the compressor seems to spin freely, but the engine really labors when the AC is on (compressor engaged). Does anyone have any ideas about what might be causing this? I didn't replace the pressure valve, but it doesn't seem like a defective valve would cause the pressure to build so high that the engine struggles to stay running. I am happy to replace parts, but was hoping for some direction. The clutch engages and disengages, the compressor spins, the old relay and the new Mitsuba relay exhibit the same behavior. I don't know what the problem might be. Thanks for any help!