2001 Cavalier 5-speed manual 2.2 241K. The only other time I had an AC problem was about 10 years ago when the original compressor died and made an obviously bad noise. Was told the main seal was shot so paid about $900 total for a new compressor and associated parts.

Then a few years ago started to notice a PAG oil leak from the control valve at the bottom of the compressor, but no other symptoms of any issues. Ran fine like that until last summer when although it was cool not cold enough - so bought one of those recharge cans and that worked fine for the rest of last summer. I know you are "supposed to" run the AC over the winter but I go out of my way to avoid doing this because 2 years ago when it was about 20 degrees here with ice and snow, when I turned on the defroster, it blew the cooling fan motor because the system pressure was too low for the compressor to kick on and I think that screwed up things with the fan somehow. Anyway, I avoided running the defroster or compressor this whole last 5 months or so since October (which is especially fun because my rear defroster/defogger doesn't work either) - until I turned it on for the first time last week. Absolutely no cooling at all. Not even a little. Popped the hood - here is what I found: Compressor appears and sounds to be working fine including the clutch turning off and on with request, cooling fan working fine too as it is supposed to, so obviously not a relay problem either. But the receiver/drier warm or maybe even hot as well as all the lines and hoses - so nothing cold or cool there either. It is going to be 84 later on this week and at that time I am going to see what happens from attempting another recharge. But if that doesn't work or only works for a few hours or days - then I am terrified that I am looking at a leak - but the thing that would be the end of the world and the worst disaster would be if that leak was in, at, or near the evaporator inside the dash. That is why I am posting this on Third Gen.

Has anyone experienced the symptoms I am describing? And is it true that there is no way to get to / replace the evaporator without an all-day nightmare of completely ripping everything and the entire dashboard out? I'm really worried. But with it getting hotter every day my time is running out.

Thanks.

Has anyone had issues with a leaking AC port schrader valve and if so - have you replaced it? I am hoping that my leak is something relatively simple like that and not the evaporator.

I'd love to find out I can just replace the valve.

I replaced my Schraeder valve. New one at NAPA.
Easy Peasy.

From what I have seen online, this whole replacing the valve thing has two variations - one that requires a pretty expensive specialty tool where you can prevent the loss of pressure assuming the system is still full or partially full or - a much cheaper (like $5 little gadget thing, I guess) that allows you to replace the valve if the system is already at or near empty. I would think that if I am able to get to the point where I have (1) found that the problem is low or no r134a and not some other (blockage, etc..) issue and (2) that I can actually find one of - or the only leak and (3) that that leak is from one of the AC port valves, that my most likely option would be the second of these. But I am hoping another can or two gets me through the summer. If it turns out that the leak is at the evaporator, that could be a death sentence for me and the car. Even a new compressor, receiver and tube would be financially near-impossible but I am hoping if that is what it needs that I can search the whole state of NC where I live to find someone who can do it cheap enough for me to afford.

Mine had almost zero pressure. It wouldn't even allow the clutch to operate.
I added R 134 and it worked for a week, then no pressure again.
I replaced the Shraeder valve with a new one from NAPA. Not expensive.
I then filled it with more R 134, and replaced the blue cap. Worked after that.

I should add, this was in my 2001 Z24 5 speed coupe. It's the one which is in limbo of being totaled by the little old lady who turned left right in front of me.

"Where did YOU come from?" ARG!!!

The black 2000 Z24 convertible is the "replacement". It's nice, but doesn't have a 5 speed or level II suspension.
I'm going to miss that.

Is the tool used for bicycle tire valves the same as the tool used for car AC schrader vavles? I keep finding this question all over the internet and conflicting answers.

It's a bit different. I tried getting out the old valve with one used for tires.
The kit from NAPA isn't that expensive. Just do it right.

This is the third time I had a problem with the AC. The first was the original compressor that developed a leak at the main shaft seal 7 years after I had the car in 2008. $100 to diagnose it and $700 to have it fixed. The second incident happened in the middle of winter a couple of years ago when it was in winter weather and the car was covered in ice and snow and I turned on the AC to defrost - which I had been trying to avoid - and I have no idea whether it was related or what - but what happened at that time was that first the compressor did not kick on and then the cooling fan blew up. Ever since repairing that myself, I have really avoided using the AC in the winter even though I know you are supposed to for the seals to stay lubricated, but I didn't want a repeat of problem 2. Then last summer in the start of May which is really when it gets hot here in NC, on the 15th of last year, the AC just flat-out was not going to cut it so I went and got one of those cans figuring that it was worth a shot. Sure enough, it was a little low on the pressure and when I got it to where it was supposed to be, the AC worked fine for the entire summer last year. Now I go to turn the AC on this year and - unlike last year when it was still pretty cool just not cold enough - I am literally getting hot air with no cooling AT ALL. Yet, the compressor is working normally as is the cooling fan. This made me wonder about the low pressure cut off switch - which apparently isn't involved despite my HOT blowing AC. I find this puzzling since I would think if the pressure so so low as to provide zero cooling at all, that it would also be so low as to prevent the compressor from even turning on.

To clarify what I meant in my last post about the cut-off switch and compressor running.......with the AC blowing so hot with zero cooling at all, my first thought was that I have some HUGE gaping hole leaking everything out of the system. But if the compressor is running, doesn't that mean that there has to be some pressure still in there so that the hole cannot be THAT huge? I ask this especially after having experienced proof of the low pressure cut of switch doing its thing in the winter when the compressor did not come on because the pressure was too low at that point - until I added refrigerant later on that spring when it was much warmer out.

So following up on my LAST post (to myself)..........I am now hearing that my car does not even HAVE a low-pressure cut-off switch. *WTF* ........this would potentially be really bad news for me - if you see that last posting and my assumption about the leak size. My assumption was that the reason the compressor did not come on in the winter was that the internal pressure was too low, given the very low outside/ambient temperature. Thus if the compressor was still running now when it is 85 outside, there must be enough refrigerant in there so that the leak must be a small one. But if the reason the compressor did not turn on in the winter was ONLY the outside/ambient temperature being so low - and had nothing to do with the internal pressure - then the leak may be - and probably is - a huge catastrophic one resulting in HOT air coming through while the compressor is running.

So my latest question is - which is it (the reason the compressor didn't turn on when it was below freezing in the 20s outside - was it because the compressor won't come on regardless of internal pressure if the outside temp is that low - and DOES MY CAR HAVE A LOW PRESSURE CUT OFF SWITCH OR NOT - or was my initial assumption correct? *ugh*

Just stick a gauge on it on the low pressure valve and see if you have pressure.
It will take less time than posting a bunch of questions.
I can't imagine your car NOT having a low pressure switch.