So my A/C has some problems with it. The A/C works some of the time and some times it doesn't. I turn my A/C on, and it works for 5 mins, then 15 mins of hot air, then the A/C will turn cold again and work for another 5 mins or so, and this continues for as long as its on. I put R134 in it the try to solve the problem, but that didn't work. Sometimes it just blows hot air when I turn on the A/C, and sometimes if I'm lucky it'll work fine. I can't figure out what the problem is. The summer is coming and I definately need the A/C. Any input would be great. Thanks

 

You say that you put R134a in your system, that is fine. But did you bother to verify the correct amount of refrigerant in the system before adding some? You can overcharge the system you know, and it will do just as you say. It will cool for a short time then cut off due to excessive pressures. The Maxima does very well with only two 12oz. cans for a total charge.

Bottom line is you need to charge the system with the amount of refrigerant, then begin to diagnose your cooling problems.

 

I had the pressure checked out at the mechanics, and its fine. I thought it was the pressure too, but it's not. And its not the compressor either. They thought it was some electrical problem, but it wasn't that either. I didn't have time for them to run other tests. So that's all I know right now. It's not the compressor, and its not the pressure.

 

Bump! Any help would be great

 

Check out your expanssion valve, its a common problem with 5th gens and 4th gens. It will work sometimes, sometimes it doesnt. I would evacuate the system, put it under vacuum for approx 30 min, and then inject dye into the system and recharge it. Alot of times the expanssion valve will get stuck or has some debris in it, and that causes the AC system to work or don't work. Dye will help detect any leaks further down the road, by lookin over the AC system with a BLACK LIGHT to detect any fluroscent dye leaking out.

 

Yeah, a mechanic said it might something to do with the valve. He said it might cost $200 for the valve, and like $200 for labor. Does that sound right? Is there another way to fix this problem without replacing the expanssion valve?

 

I paid like 70 bux for my expanssion valve last year. I managed to evacuate and recharge the AC system 3 times and it sucked all the debris out of the system. I had my AC system open for a few months- but I sealed off the open lines to prevent any debris- some must have managed to get in. I think I have the expanssion valve laying around my house somewhere if you need it. I managed to get my AC working again by just doing a simpple evacuate and recharge, but I deal with AC work all the time. It blows colder than ever before now, for some reason it never used to blow as good as I would like even when new.