A/C problem on E36

[Simon13]

My a/c in the e36 has stopped working all of a sudden, the system is still gassed when i push on the charge up valve. The compressor kicks in visibly when the a/c button is pressed but no cold air? The fan hedgehog is working but if the radio is off every time the a/c button is pressed i can hear a hissing type noise coming from the box somewhere?! Or could my dual climate digi display thing be playing up?! Everything else works fine on it all buttons lights functions etc.

Strange one is it all leaking out some how? expansion valve fubared?! I'm at a bit of a loss with it

[powelly]

There might be some gas in it but not enough, the expansion valve can be diagnosed but you need it plugged in, to an ac machine to monitor the guages.

[wellard]

Its most likely the expasion valve, its located in the heater box up by the clutch pedal,i changed quite a few under warranty at the dealer.they are a bit of a pig to do.

[DanThe]

If the compressor is energising then the gas pressure is ok, what happens to the expansion valve exactly? Can it block?

[wellard]

Iirc they block up and stop spraying the liquified gas onto the evaporator.one of the symptoms was the hissing noise from the heater box.
If you get it connected to an ac machine and check the pressures i think the outlet pressure will be too high.

[DanThe]

What happens to the excess pressure? I managed to connect a compressor up back to front on my E34 and it nearly stalled the engine, with the heat set to cold it was blowing out at nearly 20 degrees

[Simon13]

hmmm conflicting ideas. So maybe check to see if the correct gas pressure is present first then go from there,

I've got a spare expansion valve if its needed i kept off my old 328