What's wrong with my car's A/C? It works some of the time but not all the time.?

I have a 99 Mazda 626 that has had A/C problems for a of couple years. Sometimes it works, sometimes it doesn't. Typically on the freeway (or driving at high speeds) it works just fine. While driving in the city, though, it takes a while for the air to begin to cool (you can feel the A/C finally kick in when the car does a little shudder) and when it does it's hit or miss. It will cool for a few miles and then it will just blow warm air when you stop at a light.





The mechanic I talked to wants to charge me over $100 to check for a hose leak but it's got plenty of refrigerant as it does get cool. I'm think it's more likely a simple condenser problem. Any ideas of what to check first?

What's wrong with my car's A/C? It works some of the time but not all the time.?
If you can hear the compressor kick in then chances are that this is OK. Usually nothing goes wrong with this.


You problem lies under the dash board. This is called a TX Valve. ( thermal expander valve).


I had this on a similar vehicle to yours. it was a Mazda 323.


If you want to do this job yourself then you need to recapture the gas 134a (tetrafluoroethane) and then remove the unit from under the dash. Its not rocket science to do this and should take you about 20 minute to do so. It is attached inside the a plastic box called the evaporator that looks similar to a radiator. There you will find the valve. Please if doing this job always use new O rings never ever reused ones that were on the fittings already. Then you will need to take it back to a the same guys who recapured the gas and then re pump it back in. Have fun..
Reply:it's probably the expansion valve, and that's not a cheap fix





good luck