Hi all,
A/C on my 4-cyl. LE version went down in performance. I took it for cervice, and they charged it with freon. Now it cooling wery well, BUT: past 30-40 minutes of work it starts blowing extremely wet and cold air, and after a minute of doing this it stops cooling completely. I'm able to resart it only in a few minutes.
Could this be caused by too much freon in the A/C system? Or wrong freon type? (invoice said they used R-12) Any suggestions how to solve this issue? Thanks,
Vassa
Take it off Recirc. Your heavy breathing (sorry, couldn't resist... ;) Er, your breath contains moisture. On Recirc it does just that...recirculates the cabin air through the car. The moisture builds up in the mini 'eco-system' in your car is building up.
However, why it stops cooling is beyond me. One of the MDT's perhaps? Try using fresh air and see what happens...
I tried to shut recirculation off... It doesn't help, A/C doing the same damn thing!
It might have a slight overcharge but what is happening is that the evaporator is actually freezing up and melting. Those old toy?s had great AC. A work around would be to not use blower below level 3 and use warm outside air for cooling siurce (not recirculate) when possible and moderate temp a bit with temp control if needed and work with it as is as it is managable.
Did the AC system in the car have a big leak they had to fix, or sit unused and empty for a long time? If the system was exposed to the air for a long time, more moisture could get inside than the filter-drier could absorb, and the system could be icing up.
You get a few drops of water inside the sealed refrigerant system, and they collect and clog the metering orifice on the firewall. When the system stops working for a while the ice plug will melt, then it starts working again. If that's the problem, the cure is to recover all the refrigerant out of the system (running it through a big filter/drier on the machine). The you change the filter-drier on the car, pull a vacuum to get all the air out of the lines, and refill with your reclaimed refrigerant. Might have to add a bit more.
That, or the "AC Amplifier" circuit needs adjusting. That's a simple temperature control to sense ice buildup on the evaporator core, and shut the compressor off to force the core to defrost.
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No, neither big leak, nor it stood with no freon. Sounds like ice biuld up indeed. I run A/C on recirc. and Lo fan speed...
Bruce's explanation regarding moisture in the system is a likely culprit. I doubt if the amplifier needs adjusting since the OP's AC worked well in the past.
Run it on fresh - the problem should disappear. If you run on recirc, moisture builds up on the evaporator, which turns to frost, which makes the system think it's too cold and then shuts down. Once the frost melts, then it will re-start.
There lays your problem, the core is over cooling and freezing solid on the outside of it for low temps due to recirculated air and low blower speed. Use outside air and/or a higher blower speed and it will prevent the formation on ice on evaporater surface which eventually blocks air flow thru it and stops cooling. My old camary used to do it on occaision too if it was not too hot and the blower speed was to low.
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