Automotive Air Conditioning Information Forum

I agree with previous comments about some aftermarket TXVs not being up to snuff. I've experienced that myself.

If the original TXV looks good, is intact, and was working, I would blow it off carefully and reinstall it. I advise against readjusting it, though. Once you change the superheat spring-tension nut, you'll have to send it out for professional recalibration and testing or find another OEM part.

As said, Tim can get you the DEC PAG and anything else you might need.

Status update. I am not a very good mechanic. I removed the aftermarket TXV that I had installed, poured some DEC PAG-46 into the evaporator, installed OEM TXV from another Honda Civic that I had lying around. Pulled vacuum for a couple of hours while I reinstalled the blower fan under the dash. Charged system as best as could using a food scale. Came to a realization when I placed a thermometer on the vents, the air that is blowing out is very hot. I now think that I never had an issue with the main a/c components to begin with. I think the issue is with the climate control knob or the blend door actuator ( I think this is what it is called). Had I noticed this before I did everything I would have saved myself all this trouble. Again I am not a great mechanic. Do you guys have any thoughts how to proceed? Again thanks for all the advice so far.

Do you have pressure readings? Just to know if the system is working or not.

I was so discouraged that I did not bother to get the readings after I charged it. I'll get them tomorrow.

Pressure readings are as follows: Low side = 39psi, High side = 195psi, currently 96F outside temp. The OEM TXV that I installed was from a 2005 Honda Civic LX 1.7L Automatic. The vehicle I installed it on is a 2004 Honda Civic LX 1.7L Manual. I am not sure what the brand was but they did have the exact same code printed on the top of the TXV. HondaPartsNow.com has the exact same part number listed for both years so I am pretty sure they are the same.

The high side looks good but the low side is a bit elevated. With those pressures, you should be getting at least some cooling. Are you sure that you charged it to the correct amount? Specs call for 18 ounces of R-134a and 5 ounces of PAG-46. With such a small amount of refrigerant, just an ounce or two off can make a substantial difference.

One full can was 12oz of r134a, this was easy because I let it charge until it was completely empty. The second can I used a food scale which I know is not perfectly accurate but I was able to do it successfully on a 2005 Honda Civic. I have no cooling at all, in fact, the air is very hot at 140F coming from the vents. I would imagine that even if my A/C system was non-functioning, the air coming out of the vents would be around the same temperature as the cabin air temp not significantly hotter.

With air that hot coming from the vents, check the heater valve to ensure that the hot water from the engine is shutting off when the A/C is on. Try clamping off the heater hoses or, if possible, connecting the ends together using a piece of metal tubing and hose clamps. Alternatively, start the car when the engine is cold and immediately turn on the A/C. If you get cool air, then it's probably a re-heat issue. Problem could also be a blend door malfunction...maybe a cable worked its way off a pivot arm or a vacuum actuator failed.

Thanks, I will look into this.